From 32412070c22f47fe7cfb9547fc42ac25495d532a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:02 +0200 Subject: [PATCH 01/14] riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Firmware Features extension (FWFT) was added as part of the SBI 3.0 specification. Add SBI definitions to use this extension. Signed-off-by: Clément Léger Reviewed-by: Samuel Holland Tested-by: Samuel Holland Reviewed-by: Deepak Gupta Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/sbi.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 3d250824178bd5..bb077d0c912fb5 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -35,6 +35,7 @@ enum sbi_ext_id { SBI_EXT_DBCN = 0x4442434E, SBI_EXT_STA = 0x535441, SBI_EXT_NACL = 0x4E41434C, + SBI_EXT_FWFT = 0x46574654, /* Experimentals extensions must lie within this range */ SBI_EXT_EXPERIMENTAL_START = 0x08000000, @@ -402,6 +403,33 @@ enum sbi_ext_nacl_feature { #define SBI_NACL_SHMEM_SRET_X(__i) ((__riscv_xlen / 8) * (__i)) #define SBI_NACL_SHMEM_SRET_X_LAST 31 +/* SBI function IDs for FW feature extension */ +#define SBI_EXT_FWFT_SET 0x0 +#define SBI_EXT_FWFT_GET 0x1 + +enum sbi_fwft_feature_t { + SBI_FWFT_MISALIGNED_EXC_DELEG = 0x0, + SBI_FWFT_LANDING_PAD = 0x1, + SBI_FWFT_SHADOW_STACK = 0x2, + SBI_FWFT_DOUBLE_TRAP = 0x3, + SBI_FWFT_PTE_AD_HW_UPDATING = 0x4, + SBI_FWFT_POINTER_MASKING_PMLEN = 0x5, + SBI_FWFT_LOCAL_RESERVED_START = 0x6, + SBI_FWFT_LOCAL_RESERVED_END = 0x3fffffff, + SBI_FWFT_LOCAL_PLATFORM_START = 0x40000000, + SBI_FWFT_LOCAL_PLATFORM_END = 0x7fffffff, + + SBI_FWFT_GLOBAL_RESERVED_START = 0x80000000, + SBI_FWFT_GLOBAL_RESERVED_END = 0xbfffffff, + SBI_FWFT_GLOBAL_PLATFORM_START = 0xc0000000, + SBI_FWFT_GLOBAL_PLATFORM_END = 0xffffffff, +}; + +#define SBI_FWFT_PLATFORM_FEATURE_BIT BIT(30) +#define SBI_FWFT_GLOBAL_FEATURE_BIT BIT(31) + +#define SBI_FWFT_SET_FLAG_LOCK BIT(0) + /* SBI spec version fields */ #define SBI_SPEC_VERSION_DEFAULT 0x1 #define SBI_SPEC_VERSION_MAJOR_SHIFT 24 @@ -419,6 +447,11 @@ enum sbi_ext_nacl_feature { #define SBI_ERR_ALREADY_STARTED -7 #define SBI_ERR_ALREADY_STOPPED -8 #define SBI_ERR_NO_SHMEM -9 +#define SBI_ERR_INVALID_STATE -10 +#define SBI_ERR_BAD_RANGE -11 +#define SBI_ERR_TIMEOUT -12 +#define SBI_ERR_IO -13 +#define SBI_ERR_DENIED_LOCKED -14 extern unsigned long sbi_spec_version; struct sbiret { From c6909417226373e12c971c912aab477523b1953e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:03 +0200 Subject: [PATCH 02/14] riscv: sbi: remove useless parenthesis MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A few parenthesis in check for SBI version/extension were useless, remove them. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/kernel/sbi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 1989b8cade1b98..1d44c35305a96a 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -609,7 +609,7 @@ void __init sbi_init(void) } else { __sbi_rfence = __sbi_rfence_v01; } - if ((sbi_spec_version >= sbi_mk_version(0, 3)) && + if (sbi_spec_version >= sbi_mk_version(0, 3) && sbi_probe_extension(SBI_EXT_SRST)) { pr_info("SBI SRST extension detected\n"); pm_power_off = sbi_srst_power_off; @@ -617,8 +617,8 @@ void __init sbi_init(void) sbi_srst_reboot_nb.priority = 192; register_restart_handler(&sbi_srst_reboot_nb); } - if ((sbi_spec_version >= sbi_mk_version(2, 0)) && - (sbi_probe_extension(SBI_EXT_DBCN) > 0)) { + if (sbi_spec_version >= sbi_mk_version(2, 0) && + sbi_probe_extension(SBI_EXT_DBCN) > 0) { pr_info("SBI DBCN extension detected\n"); sbi_debug_console_available = true; } From 0613e8db57a2cf2948551c4177afc3139329cdc5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:04 +0200 Subject: [PATCH 03/14] riscv: sbi: add new SBI error mappings MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A few new errors have been added with SBI V3.0, maps them as close as possible to errno values. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/sbi.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index bb077d0c912fb5..0938f2a8d01bad 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -536,11 +536,21 @@ static inline int sbi_err_map_linux_errno(int err) case SBI_SUCCESS: return 0; case SBI_ERR_DENIED: + case SBI_ERR_DENIED_LOCKED: return -EPERM; case SBI_ERR_INVALID_PARAM: + case SBI_ERR_INVALID_STATE: return -EINVAL; + case SBI_ERR_BAD_RANGE: + return -ERANGE; case SBI_ERR_INVALID_ADDRESS: return -EFAULT; + case SBI_ERR_NO_SHMEM: + return -ENOMEM; + case SBI_ERR_TIMEOUT: + return -ETIMEDOUT; + case SBI_ERR_IO: + return -EIO; case SBI_ERR_NOT_SUPPORTED: case SBI_ERR_FAILURE: default: From b2567772446efa7cb3d3fa1fde50b288b1b27a0c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:05 +0200 Subject: [PATCH 04/14] riscv: sbi: add FWFT extension interface MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This SBI extensions enables supervisor mode to control feature that are under M-mode control (For instance, Svadu menvcfg ADUE bit, Ssdbltrp DTE, etc). Add an interface to set local features for a specific cpu mask as well as for the online cpu mask. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/sbi.h | 17 +++++++++++ arch/riscv/kernel/sbi.c | 57 ++++++++++++++++++++++++++++++++++++ 2 files changed, 74 insertions(+) diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 0938f2a8d01bad..341e74238aa04e 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -503,6 +503,23 @@ int sbi_remote_hfence_vvma_asid(const struct cpumask *cpu_mask, unsigned long asid); long sbi_probe_extension(int ext); +int sbi_fwft_set(u32 feature, unsigned long value, unsigned long flags); +int sbi_fwft_set_cpumask(const cpumask_t *mask, u32 feature, + unsigned long value, unsigned long flags); +/** + * sbi_fwft_set_online_cpus() - Set a feature on all online cpus + * @feature: The feature to be set + * @value: The feature value to be set + * @flags: FWFT feature set flags + * + * Return: 0 on success, appropriate linux error code otherwise. + */ +static inline int sbi_fwft_set_online_cpus(u32 feature, unsigned long value, + unsigned long flags) +{ + return sbi_fwft_set_cpumask(cpu_online_mask, feature, value, flags); +} + /* Check if current SBI specification version is 0.1 or not */ static inline int sbi_spec_is_0_1(void) { diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 1d44c35305a96a..818efafdc8e978 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -299,6 +299,63 @@ static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask, return 0; } +struct fwft_set_req { + u32 feature; + unsigned long value; + unsigned long flags; + atomic_t error; +}; + +static void cpu_sbi_fwft_set(void *arg) +{ + struct fwft_set_req *req = arg; + int ret; + + ret = sbi_fwft_set(req->feature, req->value, req->flags); + if (ret) + atomic_set(&req->error, ret); +} + +/** + * sbi_fwft_set() - Set a feature on the local hart + * @feature: The feature ID to be set + * @value: The feature value to be set + * @flags: FWFT feature set flags + * + * Return: 0 on success, appropriate linux error code otherwise. + */ +int sbi_fwft_set(u32 feature, unsigned long value, unsigned long flags) +{ + return -EOPNOTSUPP; +} + +/** + * sbi_fwft_set_cpumask() - Set a feature for the specified cpumask + * @mask: CPU mask of cpus that need the feature to be set + * @feature: The feature ID to be set + * @value: The feature value to be set + * @flags: FWFT feature set flags + * + * Return: 0 on success, appropriate linux error code otherwise. + */ +int sbi_fwft_set_cpumask(const cpumask_t *mask, u32 feature, + unsigned long value, unsigned long flags) +{ + struct fwft_set_req req = { + .feature = feature, + .value = value, + .flags = flags, + .error = ATOMIC_INIT(0), + }; + + if (feature & SBI_FWFT_GLOBAL_FEATURE_BIT) + return -EINVAL; + + on_each_cpu_mask(mask, cpu_sbi_fwft_set, &req, 1); + + return atomic_read(&req.error); +} + /** * sbi_set_timer() - Program the timer for next timer event. * @stime_value: The value after which next timer event should fire. From 2d931289844a9e3101845b4f4c34e20524936718 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:06 +0200 Subject: [PATCH 05/14] riscv: sbi: add SBI FWFT extension calls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add FWFT extension calls. This will be ratified in SBI V3.0 hence, it is provided as a separate commit that can be left out if needed. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/kernel/sbi.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 818efafdc8e978..53836a9235e320 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -299,6 +299,8 @@ static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask, return 0; } +static bool sbi_fwft_supported; + struct fwft_set_req { u32 feature; unsigned long value; @@ -326,7 +328,15 @@ static void cpu_sbi_fwft_set(void *arg) */ int sbi_fwft_set(u32 feature, unsigned long value, unsigned long flags) { - return -EOPNOTSUPP; + struct sbiret ret; + + if (!sbi_fwft_supported) + return -EOPNOTSUPP; + + ret = sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_SET, + feature, value, flags, 0, 0, 0); + + return sbi_err_map_linux_errno(ret.error); } /** @@ -348,6 +358,9 @@ int sbi_fwft_set_cpumask(const cpumask_t *mask, u32 feature, .error = ATOMIC_INIT(0), }; + if (!sbi_fwft_supported) + return -EOPNOTSUPP; + if (feature & SBI_FWFT_GLOBAL_FEATURE_BIT) return -EINVAL; @@ -679,6 +692,11 @@ void __init sbi_init(void) pr_info("SBI DBCN extension detected\n"); sbi_debug_console_available = true; } + if (sbi_spec_version >= sbi_mk_version(3, 0) && + sbi_probe_extension(SBI_EXT_FWFT)) { + pr_info("SBI FWFT extension detected\n"); + sbi_fwft_supported = true; + } } else { __sbi_set_timer = __sbi_set_timer_v01; __sbi_send_ipi = __sbi_send_ipi_v01; From 8aa5ae07f6bf26381542517c84fa1a089d8cdfac Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:07 +0200 Subject: [PATCH 06/14] riscv: misaligned: request misaligned exception from SBI MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now that the kernel can handle misaligned accesses in S-mode, request misaligned access exception delegation from SBI. This uses the FWFT SBI extension defined in SBI version 3.0. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/cpufeature.h | 3 +- arch/riscv/kernel/traps_misaligned.c | 71 +++++++++++++++++++++- arch/riscv/kernel/unaligned_access_speed.c | 8 ++- 3 files changed, 77 insertions(+), 5 deletions(-) diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h index f56b409361fbe0..dbe5970d4fe6aa 100644 --- a/arch/riscv/include/asm/cpufeature.h +++ b/arch/riscv/include/asm/cpufeature.h @@ -67,8 +67,9 @@ void __init riscv_user_isa_enable(void); _RISCV_ISA_EXT_DATA(_name, _id, _sub_exts, ARRAY_SIZE(_sub_exts), _validate) bool __init check_unaligned_access_emulated_all_cpus(void); +void unaligned_access_init(void); +int cpu_online_unaligned_access_init(unsigned int cpu); #if defined(CONFIG_RISCV_SCALAR_MISALIGNED) -void check_unaligned_access_emulated(struct work_struct *work __always_unused); void unaligned_emulation_finish(void); bool unaligned_ctl_available(void); DECLARE_PER_CPU(long, misaligned_access_speed); diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 77c788660223b3..592b1a28e897c1 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #define INSN_MATCH_LB 0x3 @@ -646,7 +647,7 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) static bool unaligned_ctl __read_mostly; -void check_unaligned_access_emulated(struct work_struct *work __always_unused) +static void check_unaligned_access_emulated(struct work_struct *work __always_unused) { int cpu = smp_processor_id(); long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); @@ -657,6 +658,13 @@ void check_unaligned_access_emulated(struct work_struct *work __always_unused) __asm__ __volatile__ ( " "REG_L" %[tmp], 1(%[ptr])\n" : [tmp] "=r" (tmp_val) : [ptr] "r" (&tmp_var) : "memory"); +} + +static int cpu_online_check_unaligned_access_emulated(unsigned int cpu) +{ + long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); + + check_unaligned_access_emulated(NULL); /* * If unaligned_ctl is already set, this means that we detected that all @@ -665,9 +673,10 @@ void check_unaligned_access_emulated(struct work_struct *work __always_unused) */ if (unlikely(unaligned_ctl && (*mas_ptr != RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED))) { pr_crit("CPU misaligned accesses non homogeneous (expected all emulated)\n"); - while (true) - cpu_relax(); + return -EINVAL; } + + return 0; } bool __init check_unaligned_access_emulated_all_cpus(void) @@ -699,4 +708,60 @@ bool __init check_unaligned_access_emulated_all_cpus(void) { return false; } +static int cpu_online_check_unaligned_access_emulated(unsigned int cpu) +{ + return 0; +} +#endif + +#ifdef CONFIG_RISCV_SBI + +static bool misaligned_traps_delegated; + +static int cpu_online_sbi_unaligned_setup(unsigned int cpu) +{ + if (sbi_fwft_set(SBI_FWFT_MISALIGNED_EXC_DELEG, 1, 0) && + misaligned_traps_delegated) { + pr_crit("Misaligned trap delegation non homogeneous (expected delegated)"); + return -EINVAL; + } + + return 0; +} + +void __init unaligned_access_init(void) +{ + int ret; + + ret = sbi_fwft_set_online_cpus(SBI_FWFT_MISALIGNED_EXC_DELEG, 1, 0); + if (ret) + return; + + misaligned_traps_delegated = true; + pr_info("SBI misaligned access exception delegation ok\n"); + /* + * Note that we don't have to take any specific action here, if + * the delegation is successful, then + * check_unaligned_access_emulated() will verify that indeed the + * platform traps on misaligned accesses. + */ +} +#else +void __init unaligned_access_init(void) {} + +static int cpu_online_sbi_unaligned_setup(unsigned int cpu __always_unused) +{ + return 0; +} #endif + +int cpu_online_unaligned_access_init(unsigned int cpu) +{ + int ret; + + ret = cpu_online_sbi_unaligned_setup(cpu); + if (ret) + return ret; + + return cpu_online_check_unaligned_access_emulated(cpu); +} diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c index b8ba13819d05e5..ae2068425fbcd2 100644 --- a/arch/riscv/kernel/unaligned_access_speed.c +++ b/arch/riscv/kernel/unaligned_access_speed.c @@ -236,6 +236,11 @@ arch_initcall_sync(lock_and_set_unaligned_access_static_branch); static int riscv_online_cpu(unsigned int cpu) { + int ret = cpu_online_unaligned_access_init(cpu); + + if (ret) + return ret; + /* We are already set since the last check */ if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN) { goto exit; @@ -248,7 +253,6 @@ static int riscv_online_cpu(unsigned int cpu) { static struct page *buf; - check_unaligned_access_emulated(NULL); buf = alloc_pages(GFP_KERNEL, MISALIGNED_BUFFER_ORDER); if (!buf) { pr_warn("Allocation failure, not measuring misaligned performance\n"); @@ -439,6 +443,8 @@ static int __init check_unaligned_access_all_cpus(void) { int cpu; + unaligned_access_init(); + if (unaligned_scalar_speed_param != RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN) { pr_info("scalar unaligned access speed set to '%s' (%lu) by command line\n", speed_str[unaligned_scalar_speed_param], unaligned_scalar_speed_param); From 843ab9ae2f966aff50d45afb07a2e29148ab29a1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:08 +0200 Subject: [PATCH 07/14] riscv: misaligned: use on_each_cpu() for scalar misaligned access probing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit schedule_on_each_cpu() was used without any good reason while documented as very slow. This call was in the boot path, so better use on_each_cpu() for scalar misaligned checking. Vector misaligned check still needs to use schedule_on_each_cpu() since it requires irqs to be enabled but that's less of a problem since this code is ran in a kthread. Add a comment to explicit that. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Signed-off-by: Linux RISC-V bot --- arch/riscv/kernel/traps_misaligned.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 592b1a28e897c1..34b4a4e9dfca69 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -627,6 +627,10 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) { int cpu; + /* + * While being documented as very slow, schedule_on_each_cpu() is used since + * kernel_vector_begin() expects irqs to be enabled or it will panic() + */ schedule_on_each_cpu(check_vector_unaligned_access_emulated); for_each_online_cpu(cpu) @@ -647,7 +651,7 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) static bool unaligned_ctl __read_mostly; -static void check_unaligned_access_emulated(struct work_struct *work __always_unused) +static void check_unaligned_access_emulated(void *arg __always_unused) { int cpu = smp_processor_id(); long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); @@ -688,7 +692,7 @@ bool __init check_unaligned_access_emulated_all_cpus(void) * accesses emulated since tasks requesting such control can run on any * CPU. */ - schedule_on_each_cpu(check_unaligned_access_emulated); + on_each_cpu(check_unaligned_access_emulated, NULL, 1); for_each_online_cpu(cpu) if (per_cpu(misaligned_access_speed, cpu) From d5b7372f383380b3ba7d86922d734dcdafa20635 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:09 +0200 Subject: [PATCH 08/14] riscv: misaligned: use correct CONFIG_ ifdef for misaligned_access_speed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit misaligned_access_speed is defined under CONFIG_RISCV_SCALAR_MISALIGNED but was used under CONFIG_RISCV_PROBE_UNALIGNED_ACCESS. Fix that by using the correct config option. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Signed-off-by: Linux RISC-V bot --- arch/riscv/kernel/traps_misaligned.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 34b4a4e9dfca69..e551ba17f557cf 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -369,7 +369,7 @@ static int handle_scalar_misaligned_load(struct pt_regs *regs) perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); -#ifdef CONFIG_RISCV_PROBE_UNALIGNED_ACCESS +#ifdef CONFIG_RISCV_SCALAR_MISALIGNED *this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED; #endif From dd8836dcda34f5f2de8e0a4127e2c65f374828ed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:10 +0200 Subject: [PATCH 09/14] riscv: misaligned: move emulated access uniformity check in a function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Split the code that check for the uniformity of misaligned accesses performance on all cpus from check_unaligned_access_emulated_all_cpus() to its own function which will be used for delegation check. No functional changes intended. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Signed-off-by: Linux RISC-V bot --- arch/riscv/kernel/traps_misaligned.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index e551ba17f557cf..287ec37021c8b9 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -647,6 +647,18 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) } #endif +static bool all_cpus_unaligned_scalar_access_emulated(void) +{ + int cpu; + + for_each_online_cpu(cpu) + if (per_cpu(misaligned_access_speed, cpu) != + RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED) + return false; + + return true; +} + #ifdef CONFIG_RISCV_SCALAR_MISALIGNED static bool unaligned_ctl __read_mostly; @@ -685,8 +697,6 @@ static int cpu_online_check_unaligned_access_emulated(unsigned int cpu) bool __init check_unaligned_access_emulated_all_cpus(void) { - int cpu; - /* * We can only support PR_UNALIGN controls if all CPUs have misaligned * accesses emulated since tasks requesting such control can run on any @@ -694,10 +704,8 @@ bool __init check_unaligned_access_emulated_all_cpus(void) */ on_each_cpu(check_unaligned_access_emulated, NULL, 1); - for_each_online_cpu(cpu) - if (per_cpu(misaligned_access_speed, cpu) - != RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED) - return false; + if (!all_cpus_unaligned_scalar_access_emulated()) + return false; unaligned_ctl = true; return true; From 6cf0124b73a0db41f287fc010cc4a9ba03a023a8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:11 +0200 Subject: [PATCH 10/14] riscv: misaligned: add a function to check misalign trap delegability MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Checking for the delegability of the misaligned access trap is needed for the KVM FWFT extension implementation. Add a function to get the delegability of the misaligned trap exception. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/cpufeature.h | 9 +++++++++ arch/riscv/kernel/traps_misaligned.c | 17 +++++++++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h index dbe5970d4fe6aa..09a5183345d43d 100644 --- a/arch/riscv/include/asm/cpufeature.h +++ b/arch/riscv/include/asm/cpufeature.h @@ -80,6 +80,15 @@ static inline bool unaligned_ctl_available(void) } #endif +#ifdef CONFIG_RISCV_MISALIGNED +bool misaligned_traps_can_delegate(void); +#else +static inline bool misaligned_traps_can_delegate(void) +{ + return false; +} +#endif + bool __init check_vector_unaligned_access_emulated_all_cpus(void); #if defined(CONFIG_RISCV_VECTOR_MISALIGNED) void check_vector_unaligned_access_emulated(struct work_struct *work __always_unused); diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 287ec37021c8b9..f3ab84bc463234 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -726,10 +726,10 @@ static int cpu_online_check_unaligned_access_emulated(unsigned int cpu) } #endif -#ifdef CONFIG_RISCV_SBI - static bool misaligned_traps_delegated; +#ifdef CONFIG_RISCV_SBI + static int cpu_online_sbi_unaligned_setup(unsigned int cpu) { if (sbi_fwft_set(SBI_FWFT_MISALIGNED_EXC_DELEG, 1, 0) && @@ -765,6 +765,7 @@ static int cpu_online_sbi_unaligned_setup(unsigned int cpu __always_unused) { return 0; } + #endif int cpu_online_unaligned_access_init(unsigned int cpu) @@ -777,3 +778,15 @@ int cpu_online_unaligned_access_init(unsigned int cpu) return cpu_online_check_unaligned_access_emulated(cpu); } + +bool misaligned_traps_can_delegate(void) +{ + /* + * Either we successfully requested misaligned traps delegation for all + * CPUs, or the SBI does not implement the FWFT extension but delegated + * the exception by default. + */ + return misaligned_traps_delegated || + all_cpus_unaligned_scalar_access_emulated(); +} +EXPORT_SYMBOL_GPL(misaligned_traps_can_delegate); From 67d4465b5c3264490709bb66613966d09c15db87 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:12 +0200 Subject: [PATCH 11/14] RISC-V: KVM: add SBI extension init()/deinit() functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The FWFT SBI extension will need to dynamically allocate memory and do init time specific initialization. Add an init/deinit callbacks that allows to do so. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/kvm_vcpu_sbi.h | 9 +++++++++ arch/riscv/kvm/vcpu.c | 2 ++ arch/riscv/kvm/vcpu_sbi.c | 26 ++++++++++++++++++++++++++ 3 files changed, 37 insertions(+) diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h index 4ed6203cdd3079..bcb90757b1495a 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h @@ -49,6 +49,14 @@ struct kvm_vcpu_sbi_extension { /* Extension specific probe function */ unsigned long (*probe)(struct kvm_vcpu *vcpu); + + /* + * Init/deinit function called once during VCPU init/destroy. These + * might be use if the SBI extensions need to allocate or do specific + * init time only configuration. + */ + int (*init)(struct kvm_vcpu *vcpu); + void (*deinit)(struct kvm_vcpu *vcpu); }; void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run); @@ -69,6 +77,7 @@ const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext( bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx); int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run); void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu); +void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu); int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu, unsigned long reg_num, unsigned long *reg_val); diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 60d684c76c5873..877bcc85c06709 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -185,6 +185,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) { + kvm_riscv_vcpu_sbi_deinit(vcpu); + /* Cleanup VCPU AIA context */ kvm_riscv_vcpu_aia_deinit(vcpu); diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index d1c83a77735e05..3139f171c20fcd 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -508,5 +508,31 @@ void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu) scontext->ext_status[idx] = ext->default_disabled ? KVM_RISCV_SBI_EXT_STATUS_DISABLED : KVM_RISCV_SBI_EXT_STATUS_ENABLED; + + if (ext->init && ext->init(vcpu) != 0) + scontext->ext_status[idx] = KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE; + } +} + +void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context; + const struct kvm_riscv_sbi_extension_entry *entry; + const struct kvm_vcpu_sbi_extension *ext; + int idx, i; + + for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) { + entry = &sbi_ext[i]; + ext = entry->ext_ptr; + idx = entry->ext_idx; + + if (idx < 0 || idx >= ARRAY_SIZE(scontext->ext_status)) + continue; + + if (scontext->ext_status[idx] == KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE || + !ext->deinit) + continue; + + ext->deinit(vcpu); } } From d169584d3090991bea525c53cbddedb8328b7e7f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:13 +0200 Subject: [PATCH 12/14] RISC-V: KVM: add SBI extension reset callback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, only the STA extension needed a reset function but that's going to be the case for FWFT as well. Add a reset callback that can be implemented by SBI extensions. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/kvm_host.h | 1 - arch/riscv/include/asm/kvm_vcpu_sbi.h | 2 ++ arch/riscv/kvm/vcpu.c | 2 +- arch/riscv/kvm/vcpu_sbi.c | 24 ++++++++++++++++++++++++ arch/riscv/kvm/vcpu_sbi_sta.c | 3 ++- 5 files changed, 29 insertions(+), 3 deletions(-) diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 0e9c2fab637872..4fa02e08214205 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -407,7 +407,6 @@ void __kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu); void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu); bool kvm_riscv_vcpu_stopped(struct kvm_vcpu *vcpu); -void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu); void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu); #endif /* __RISCV_KVM_HOST_H__ */ diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h index bcb90757b1495a..cb68b3a57c8f8d 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h @@ -57,6 +57,7 @@ struct kvm_vcpu_sbi_extension { */ int (*init)(struct kvm_vcpu *vcpu); void (*deinit)(struct kvm_vcpu *vcpu); + void (*reset)(struct kvm_vcpu *vcpu); }; void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run); @@ -78,6 +79,7 @@ bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx); int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run); void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu); void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu); +void kvm_riscv_vcpu_sbi_reset(struct kvm_vcpu *vcpu); int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu, unsigned long reg_num, unsigned long *reg_val); diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 877bcc85c06709..542747e2c7f508 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -94,7 +94,7 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) vcpu->arch.hfence_tail = 0; memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue)); - kvm_riscv_vcpu_sbi_sta_reset(vcpu); + kvm_riscv_vcpu_sbi_reset(vcpu); /* Reset the guest CSRs for hotplug usecase */ if (loaded) diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index 3139f171c20fcd..50be079b552836 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -536,3 +536,27 @@ void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu) ext->deinit(vcpu); } } + +void kvm_riscv_vcpu_sbi_reset(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context; + const struct kvm_riscv_sbi_extension_entry *entry; + const struct kvm_vcpu_sbi_extension *ext; + int idx, i; + + for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) { + entry = &sbi_ext[i]; + ext = entry->ext_ptr; + idx = entry->ext_idx; + + if (idx < 0 || idx >= ARRAY_SIZE(scontext->ext_status)) + continue; + + if (scontext->ext_status[idx] != KVM_RISCV_SBI_EXT_STATUS_ENABLED || + !ext->reset) + continue; + + ext->reset(vcpu); + } +} + diff --git a/arch/riscv/kvm/vcpu_sbi_sta.c b/arch/riscv/kvm/vcpu_sbi_sta.c index 5f35427114c1da..cc6cb7c8f0e411 100644 --- a/arch/riscv/kvm/vcpu_sbi_sta.c +++ b/arch/riscv/kvm/vcpu_sbi_sta.c @@ -16,7 +16,7 @@ #include #include -void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu) +static void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu) { vcpu->arch.sta.shmem = INVALID_GPA; vcpu->arch.sta.last_steal = 0; @@ -156,6 +156,7 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta = { .extid_end = SBI_EXT_STA, .handler = kvm_sbi_ext_sta_handler, .probe = kvm_sbi_ext_sta_probe, + .reset = kvm_riscv_vcpu_sbi_sta_reset, }; int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu, From 1e0b17f671537b7a41586efd160faa15f80e2f4c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:14 +0200 Subject: [PATCH 13/14] RISC-V: KVM: add support for FWFT SBI extension MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add basic infrastructure to support the FWFT extension in KVM. Signed-off-by: Clément Léger Reviewed-by: Andrew Jones Reviewed-by: Atish Patra Signed-off-by: Linux RISC-V bot --- arch/riscv/include/asm/kvm_host.h | 4 + arch/riscv/include/asm/kvm_vcpu_sbi.h | 1 + arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 29 +++ arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu_sbi.c | 4 + arch/riscv/kvm/vcpu_sbi_fwft.c | 216 +++++++++++++++++++++ 7 files changed, 256 insertions(+) create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h create mode 100644 arch/riscv/kvm/vcpu_sbi_fwft.c diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 4fa02e08214205..c3f880763b9aa8 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -281,6 +282,9 @@ struct kvm_vcpu_arch { /* Performance monitoring context */ struct kvm_pmu pmu_context; + /* Firmware feature SBI extension context */ + struct kvm_sbi_fwft fwft_context; + /* 'static' configurations which are set only once */ struct kvm_vcpu_config cfg; diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h index cb68b3a57c8f8d..ffd03fed0c0638 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h @@ -98,6 +98,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_susp; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta; +extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_fwft; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental; extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor; diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h new file mode 100644 index 00000000000000..9ba84135575870 --- /dev/null +++ b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2025 Rivos Inc. + * + * Authors: + * Clément Léger + */ + +#ifndef __KVM_VCPU_RISCV_FWFT_H +#define __KVM_VCPU_RISCV_FWFT_H + +#include + +struct kvm_sbi_fwft_feature; + +struct kvm_sbi_fwft_config { + const struct kvm_sbi_fwft_feature *feature; + bool supported; + unsigned long flags; +}; + +/* FWFT data structure per vcpu */ +struct kvm_sbi_fwft { + struct kvm_sbi_fwft_config *configs; +}; + +#define vcpu_to_fwft(vcpu) (&(vcpu)->arch.fwft_context) + +#endif /* !__KVM_VCPU_RISCV_FWFT_H */ diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index 5f59fd226cc57a..5ba77a3d9f6e4e 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/asm/kvm.h @@ -204,6 +204,7 @@ enum KVM_RISCV_SBI_EXT_ID { KVM_RISCV_SBI_EXT_DBCN, KVM_RISCV_SBI_EXT_STA, KVM_RISCV_SBI_EXT_SUSP, + KVM_RISCV_SBI_EXT_FWFT, KVM_RISCV_SBI_EXT_MAX, }; diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index 4e0bba91d2841d..06e2d52a9b88a3 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -26,6 +26,7 @@ kvm-y += vcpu_onereg.o kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o kvm-y += vcpu_sbi.o kvm-y += vcpu_sbi_base.o +kvm-y += vcpu_sbi_fwft.o kvm-y += vcpu_sbi_hsm.o kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_sbi_pmu.o kvm-y += vcpu_sbi_replace.o diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c index 50be079b552836..0748810c0252e2 100644 --- a/arch/riscv/kvm/vcpu_sbi.c +++ b/arch/riscv/kvm/vcpu_sbi.c @@ -78,6 +78,10 @@ static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = { .ext_idx = KVM_RISCV_SBI_EXT_STA, .ext_ptr = &vcpu_sbi_ext_sta, }, + { + .ext_idx = KVM_RISCV_SBI_EXT_FWFT, + .ext_ptr = &vcpu_sbi_ext_fwft, + }, { .ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL, .ext_ptr = &vcpu_sbi_ext_experimental, diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c new file mode 100644 index 00000000000000..b0f66c7bf010e9 --- /dev/null +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025 Rivos Inc. + * + * Authors: + * Clément Léger + */ + +#include +#include +#include +#include +#include +#include +#include + +struct kvm_sbi_fwft_feature { + /** + * @id: Feature ID + */ + enum sbi_fwft_feature_t id; + + /** + * @supported: Check if the feature is supported on the vcpu + * + * This callback is optional, if not provided the feature is assumed to + * be supported + */ + bool (*supported)(struct kvm_vcpu *vcpu); + + /** + * @set: Set the feature value + * + * Return SBI_SUCCESS on success or an SBI error (SBI_ERR_*) + * + * This callback is mandatory + */ + long (*set)(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf, unsigned long value); + + /** + * @get: Get the feature current value + * + * Return SBI_SUCCESS on success or an SBI error (SBI_ERR_*) + * + * This callback is mandatory + */ + long (*get)(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf, unsigned long *value); +}; + +static const enum sbi_fwft_feature_t kvm_fwft_defined_features[] = { + SBI_FWFT_MISALIGNED_EXC_DELEG, + SBI_FWFT_LANDING_PAD, + SBI_FWFT_SHADOW_STACK, + SBI_FWFT_DOUBLE_TRAP, + SBI_FWFT_PTE_AD_HW_UPDATING, + SBI_FWFT_POINTER_MASKING_PMLEN, +}; + +static bool kvm_fwft_is_defined_feature(enum sbi_fwft_feature_t feature) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(kvm_fwft_defined_features); i++) { + if (kvm_fwft_defined_features[i] == feature) + return true; + } + + return false; +} + +static const struct kvm_sbi_fwft_feature features[] = { +}; + +static struct kvm_sbi_fwft_config * +kvm_sbi_fwft_get_config(struct kvm_vcpu *vcpu, enum sbi_fwft_feature_t feature) +{ + int i; + struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu); + + for (i = 0; i < ARRAY_SIZE(features); i++) { + if (fwft->configs[i].feature->id == feature) + return &fwft->configs[i]; + } + + return NULL; +} + +static int kvm_fwft_get_feature(struct kvm_vcpu *vcpu, u32 feature, + struct kvm_sbi_fwft_config **conf) +{ + struct kvm_sbi_fwft_config *tconf; + + tconf = kvm_sbi_fwft_get_config(vcpu, feature); + if (!tconf) { + if (kvm_fwft_is_defined_feature(feature)) + return SBI_ERR_NOT_SUPPORTED; + + return SBI_ERR_DENIED; + } + + if (!tconf->supported) + return SBI_ERR_NOT_SUPPORTED; + + *conf = tconf; + + return SBI_SUCCESS; +} + +static int kvm_sbi_fwft_set(struct kvm_vcpu *vcpu, u32 feature, + unsigned long value, unsigned long flags) +{ + int ret; + struct kvm_sbi_fwft_config *conf; + + ret = kvm_fwft_get_feature(vcpu, feature, &conf); + if (ret) + return ret; + + if ((flags & ~SBI_FWFT_SET_FLAG_LOCK) != 0) + return SBI_ERR_INVALID_PARAM; + + if (conf->flags & SBI_FWFT_SET_FLAG_LOCK) + return SBI_ERR_DENIED_LOCKED; + + conf->flags = flags; + + return conf->feature->set(vcpu, conf, value); +} + +static int kvm_sbi_fwft_get(struct kvm_vcpu *vcpu, unsigned long feature, + unsigned long *value) +{ + int ret; + struct kvm_sbi_fwft_config *conf; + + ret = kvm_fwft_get_feature(vcpu, feature, &conf); + if (ret) + return ret; + + return conf->feature->get(vcpu, conf, value); +} + +static int kvm_sbi_ext_fwft_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, + struct kvm_vcpu_sbi_return *retdata) +{ + int ret; + struct kvm_cpu_context *cp = &vcpu->arch.guest_context; + unsigned long funcid = cp->a6; + + switch (funcid) { + case SBI_EXT_FWFT_SET: + ret = kvm_sbi_fwft_set(vcpu, cp->a0, cp->a1, cp->a2); + break; + case SBI_EXT_FWFT_GET: + ret = kvm_sbi_fwft_get(vcpu, cp->a0, &retdata->out_val); + break; + default: + ret = SBI_ERR_NOT_SUPPORTED; + break; + } + + retdata->err_val = ret; + + return 0; +} + +static int kvm_sbi_ext_fwft_init(struct kvm_vcpu *vcpu) +{ + struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu); + const struct kvm_sbi_fwft_feature *feature; + struct kvm_sbi_fwft_config *conf; + int i; + + fwft->configs = kcalloc(ARRAY_SIZE(features), sizeof(struct kvm_sbi_fwft_config), + GFP_KERNEL); + if (!fwft->configs) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(features); i++) { + feature = &features[i]; + conf = &fwft->configs[i]; + if (feature->supported) + conf->supported = feature->supported(vcpu); + else + conf->supported = true; + + conf->feature = feature; + } + + return 0; +} + +static void kvm_sbi_ext_fwft_deinit(struct kvm_vcpu *vcpu) +{ + struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu); + + kfree(fwft->configs); +} + +static void kvm_sbi_ext_fwft_reset(struct kvm_vcpu *vcpu) +{ + int i; + struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu); + + for (i = 0; i < ARRAY_SIZE(features); i++) + fwft->configs[i].flags = 0; +} + +const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_fwft = { + .extid_start = SBI_EXT_FWFT, + .extid_end = SBI_EXT_FWFT, + .handler = kvm_sbi_ext_fwft_handler, + .init = kvm_sbi_ext_fwft_init, + .deinit = kvm_sbi_ext_fwft_deinit, + .reset = kvm_sbi_ext_fwft_reset, +}; From bec17ffd40a0ac48dd8d9995f678a44ff4ce4f80 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20L=C3=A9ger?= Date: Thu, 15 May 2025 10:22:15 +0200 Subject: [PATCH 14/14] RISC-V: KVM: add support for SBI_FWFT_MISALIGNED_DELEG MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit SBI_FWFT_MISALIGNED_DELEG needs hedeleg to be modified to delegate misaligned load/store exceptions. Save and restore it during CPU load/put. Signed-off-by: Clément Léger Reviewed-by: Deepak Gupta Reviewed-by: Andrew Jones Signed-off-by: Linux RISC-V bot --- arch/riscv/kvm/vcpu_sbi_fwft.c | 41 ++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c index b0f66c7bf010e9..6770c043bbcb35 100644 --- a/arch/riscv/kvm/vcpu_sbi_fwft.c +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c @@ -14,6 +14,8 @@ #include #include +#define MIS_DELEG (BIT_ULL(EXC_LOAD_MISALIGNED) | BIT_ULL(EXC_STORE_MISALIGNED)) + struct kvm_sbi_fwft_feature { /** * @id: Feature ID @@ -68,7 +70,46 @@ static bool kvm_fwft_is_defined_feature(enum sbi_fwft_feature_t feature) return false; } +static bool kvm_sbi_fwft_misaligned_delegation_supported(struct kvm_vcpu *vcpu) +{ + return misaligned_traps_can_delegate(); +} + +static long kvm_sbi_fwft_set_misaligned_delegation(struct kvm_vcpu *vcpu, + struct kvm_sbi_fwft_config *conf, + unsigned long value) +{ + struct kvm_vcpu_config *cfg = &vcpu->arch.cfg; + + if (value == 1) { + cfg->hedeleg |= MIS_DELEG; + csr_set(CSR_HEDELEG, MIS_DELEG); + } else if (value == 0) { + cfg->hedeleg &= ~MIS_DELEG; + csr_clear(CSR_HEDELEG, MIS_DELEG); + } else { + return SBI_ERR_INVALID_PARAM; + } + + return SBI_SUCCESS; +} + +static long kvm_sbi_fwft_get_misaligned_delegation(struct kvm_vcpu *vcpu, + struct kvm_sbi_fwft_config *conf, + unsigned long *value) +{ + *value = (csr_read(CSR_HEDELEG) & MIS_DELEG) == MIS_DELEG; + + return SBI_SUCCESS; +} + static const struct kvm_sbi_fwft_feature features[] = { + { + .id = SBI_FWFT_MISALIGNED_EXC_DELEG, + .supported = kvm_sbi_fwft_misaligned_delegation_supported, + .set = kvm_sbi_fwft_set_misaligned_delegation, + .get = kvm_sbi_fwft_get_misaligned_delegation, + }, }; static struct kvm_sbi_fwft_config *