On Fri, May 23, 2025 at 3:52 PM Clément Léger cleger@rivosinc.com wrote:
Add basic infrastructure to support the FWFT extension in KVM.
Signed-off-by: Clément Léger cleger@rivosinc.com Reviewed-by: Andrew Jones ajones@ventanamicro.com Reviewed-by: Atish Patra atishp@rivosinc.com
Queued this patch for Linux-6.17
Thanks, Anup
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 4fa02e082142..c3f880763b9a 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -19,6 +19,7 @@ #include <asm/kvm_vcpu_fp.h> #include <asm/kvm_vcpu_insn.h> #include <asm/kvm_vcpu_sbi.h> +#include <asm/kvm_vcpu_sbi_fwft.h> #include <asm/kvm_vcpu_timer.h> #include <asm/kvm_vcpu_pmu.h>
@@ -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 cb68b3a57c8f..ffd03fed0c06 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 000000000000..9ba841355758 --- /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 <cleger@rivosinc.com>- */
+#ifndef __KVM_VCPU_RISCV_FWFT_H +#define __KVM_VCPU_RISCV_FWFT_H
+#include <asm/sbi.h>
+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 5f59fd226cc5..5ba77a3d9f6e 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 4e0bba91d284..06e2d52a9b88 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 50be079b5528..0748810c0252 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 000000000000..b0f66c7bf010 --- /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 <cleger@rivosinc.com>- */
+#include <linux/errno.h> +#include <linux/err.h> +#include <linux/kvm_host.h> +#include <asm/cpufeature.h> +#include <asm/sbi.h> +#include <asm/kvm_vcpu_sbi.h> +#include <asm/kvm_vcpu_sbi_fwft.h>
+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);elseconf->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,+};
2.49.0