[Backport]: KVM 支持 SBI FWFT 扩展优化 Fwft

arch/riscv/include/asm/kvm_vcpu_sbi.h

@@ -59,34 +59,36 @@ struct kvm_vcpu_sbi_extension {
 	void (*deinit)(struct kvm_vcpu *vcpu);
 
 	void (*reset)(struct kvm_vcpu *vcpu);
+
+	unsigned long state_reg_subtype;
+	unsigned long (*get_state_reg_count)(struct kvm_vcpu *vcpu);
+	int (*get_state_reg_id)(struct kvm_vcpu *vcpu, int index, u64 *reg_id);
+	int (*get_state_reg)(struct kvm_vcpu *vcpu, unsigned long reg_num,
+			     unsigned long reg_size, void *reg_val);
+	int (*set_state_reg)(struct kvm_vcpu *vcpu, unsigned long reg_num,
+			     unsigned long reg_size, const void *reg_val);
 };
 
 void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run);
 void kvm_riscv_vcpu_sbi_system_reset(struct kvm_vcpu *vcpu,
 				     struct kvm_run *run,
 				     u32 type, u64 flags);
 int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_riscv_vcpu_reg_indices_sbi_ext(struct kvm_vcpu *vcpu, u64 __user *uindices);
 int kvm_riscv_vcpu_set_reg_sbi_ext(struct kvm_vcpu *vcpu,
 				   const struct kvm_one_reg *reg);
 int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
 				   const struct kvm_one_reg *reg);
-int kvm_riscv_vcpu_set_reg_sbi(struct kvm_vcpu *vcpu,
-			       const struct kvm_one_reg *reg);
-int kvm_riscv_vcpu_get_reg_sbi(struct kvm_vcpu *vcpu,
-			       const struct kvm_one_reg *reg);
+int kvm_riscv_vcpu_reg_indices_sbi(struct kvm_vcpu *vcpu, u64 __user *uindices);
+int kvm_riscv_vcpu_set_reg_sbi(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
+int kvm_riscv_vcpu_get_reg_sbi(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
 				struct kvm_vcpu *vcpu, unsigned long extid);
-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);
-int kvm_riscv_vcpu_set_reg_sbi_sta(struct kvm_vcpu *vcpu, unsigned long reg_num,
-				   unsigned long reg_val);
-
 #ifdef CONFIG_RISCV_SBI_V01
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01;
 #endif

arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h

@@ -16,12 +16,17 @@ struct kvm_sbi_fwft_feature;
 struct kvm_sbi_fwft_config {
 	const struct kvm_sbi_fwft_feature *feature;
 	bool supported;
+	bool enabled;
 	unsigned long flags;
 };
 
 /* FWFT data structure per vcpu */
 struct kvm_sbi_fwft {
 	struct kvm_sbi_fwft_config *configs;
+#ifndef CONFIG_32BIT
+	bool have_vs_pmlen_7;
+	bool have_vs_pmlen_16;
+#endif
 };
 
 #define vcpu_to_fwft(vcpu) (&(vcpu)->arch.fwft_context)

arch/riscv/include/uapi/asm/kvm.h

@@ -223,6 +223,18 @@ struct kvm_riscv_sbi_sta {
 	unsigned long shmem_hi;
 };
 
+struct kvm_riscv_sbi_fwft_feature {
+	unsigned long enable;
+	unsigned long flags;
+	unsigned long value;
+};
+
+/* SBI FWFT extension registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
+struct kvm_riscv_sbi_fwft {
+	struct kvm_riscv_sbi_fwft_feature misaligned_deleg;
+	struct kvm_riscv_sbi_fwft_feature pointer_masking;
+};
+
 /* Possible states for kvm_riscv_timer */
 #define KVM_RISCV_TIMER_STATE_OFF	0
 #define KVM_RISCV_TIMER_STATE_ON	1
@@ -309,6 +321,9 @@ struct kvm_riscv_sbi_sta {
 #define KVM_REG_RISCV_SBI_STA		(0x0 << KVM_REG_RISCV_SUBTYPE_SHIFT)
 #define KVM_REG_RISCV_SBI_STA_REG(name)		\
 		(offsetof(struct kvm_riscv_sbi_sta, name) / sizeof(unsigned long))
+#define KVM_REG_RISCV_SBI_FWFT		(0x1 << KVM_REG_RISCV_SUBTYPE_SHIFT)
+#define KVM_REG_RISCV_SBI_FWFT_REG(name)	\
+		(offsetof(struct kvm_riscv_sbi_fwft, name) / sizeof(unsigned long))
 
 /* Device Control API: RISC-V AIA */
 #define KVM_DEV_RISCV_APLIC_ALIGN		0x1000

arch/riscv/kvm/vcpu.c

@@ -125,6 +125,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 
 	/* Mark this VCPU never ran */
 	vcpu->arch.ran_atleast_once = false;
+
+	vcpu->arch.cfg.hedeleg = KVM_HEDELEG_DEFAULT;
 	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
 	bitmap_zero(vcpu->arch.isa, RISCV_ISA_EXT_MAX);
 
@@ -606,7 +608,6 @@ static void kvm_riscv_vcpu_setup_config(struct kvm_vcpu *vcpu)
 			cfg->hstateen0 |= SMSTATEEN0_SSTATEEN0;
 	}
 
-	cfg->hedeleg = KVM_HEDELEG_DEFAULT;
 	if (vcpu->guest_debug)
 		cfg->hedeleg &= ~BIT(EXC_BREAKPOINT);
 }

arch/riscv/kvm/vcpu_onereg.c

@@ -23,7 +23,7 @@
 #define KVM_ISA_EXT_ARR(ext)		\
 [KVM_RISCV_ISA_EXT_##ext] = RISCV_ISA_EXT_##ext
 
-/* Mapping between KVM ISA Extension ID & Host ISA extension ID */
+/* Mapping between KVM ISA Extension ID & guest ISA extension ID */
 static const unsigned long kvm_isa_ext_arr[] = {
 	/* Single letter extensions (alphabetically sorted) */
 	[KVM_RISCV_ISA_EXT_A] = RISCV_ISA_EXT_a,
@@ -35,7 +35,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
 	[KVM_RISCV_ISA_EXT_M] = RISCV_ISA_EXT_m,
 	[KVM_RISCV_ISA_EXT_V] = RISCV_ISA_EXT_v,
 	/* Multi letter extensions (alphabetically sorted) */
-	[KVM_RISCV_ISA_EXT_SMNPM] = RISCV_ISA_EXT_SSNPM,
+	KVM_ISA_EXT_ARR(SMNPM),
 	KVM_ISA_EXT_ARR(SMSTATEEN),
 	KVM_ISA_EXT_ARR(SSAIA),
 	KVM_ISA_EXT_ARR(SSNPM),
@@ -119,6 +119,36 @@ static unsigned long kvm_riscv_vcpu_base2isa_ext(unsigned long base_ext)
 	return KVM_RISCV_ISA_EXT_MAX;
 }
 
+static int kvm_riscv_vcpu_isa_check_host(unsigned long kvm_ext, unsigned long *guest_ext)
+{
+	unsigned long host_ext;
+
+	if (kvm_ext >= KVM_RISCV_ISA_EXT_MAX ||
+	    kvm_ext >= ARRAY_SIZE(kvm_isa_ext_arr))
+		return -ENOENT;
+
+	*guest_ext = kvm_isa_ext_arr[kvm_ext];
+	switch (*guest_ext) {
+	case RISCV_ISA_EXT_SMNPM:
+		/*
+		 * Pointer masking effective in (H)S-mode is provided by the
+		 * Smnpm extension, so that extension is reported to the guest,
+		 * even though the CSR bits for configuring VS-mode pointer
+		 * masking on the host side are part of the Ssnpm extension.
+		 */
+		host_ext = RISCV_ISA_EXT_SSNPM;
+		break;
+	default:
+		host_ext = *guest_ext;
+		break;
+	}
+
+	if (!__riscv_isa_extension_available(NULL, host_ext))
+		return -ENOENT;
+
+	return 0;
+}
+
 static bool kvm_riscv_vcpu_isa_enable_allowed(unsigned long ext)
 {
 	switch (ext) {
@@ -150,7 +180,6 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
 	case KVM_RISCV_ISA_EXT_C:
 	case KVM_RISCV_ISA_EXT_I:
 	case KVM_RISCV_ISA_EXT_M:
-	case KVM_RISCV_ISA_EXT_SMNPM:
 	case KVM_RISCV_ISA_EXT_SSNPM:
 	/* There is not architectural config bit to disable sscofpmf completely */
 	case KVM_RISCV_ISA_EXT_SSCOFPMF:
@@ -231,13 +260,13 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
 
 void kvm_riscv_vcpu_setup_isa(struct kvm_vcpu *vcpu)
 {
-	unsigned long host_isa, i;
+	unsigned long guest_ext, i;
 
 	for (i = 0; i < ARRAY_SIZE(kvm_isa_ext_arr); i++) {
-		host_isa = kvm_isa_ext_arr[i];
-		if (__riscv_isa_extension_available(NULL, host_isa) &&
-		    kvm_riscv_vcpu_isa_enable_allowed(i))
-			set_bit(host_isa, vcpu->arch.isa);
+		if (kvm_riscv_vcpu_isa_check_host(i, &guest_ext))
+			continue;
+		if (kvm_riscv_vcpu_isa_enable_allowed(i))
+			set_bit(guest_ext, vcpu->arch.isa);
 	}
 }
 
@@ -636,18 +665,15 @@ static int riscv_vcpu_get_isa_ext_single(struct kvm_vcpu *vcpu,
 					 unsigned long reg_num,
 					 unsigned long *reg_val)
 {
-	unsigned long host_isa_ext;
-
-	if (reg_num >= KVM_RISCV_ISA_EXT_MAX ||
-	    reg_num >= ARRAY_SIZE(kvm_isa_ext_arr))
-		return -ENOENT;
+	unsigned long guest_ext;
+	int ret;
 
-	host_isa_ext = kvm_isa_ext_arr[reg_num];
-	if (!__riscv_isa_extension_available(NULL, host_isa_ext))
-		return -ENOENT;
+	ret = kvm_riscv_vcpu_isa_check_host(reg_num, &guest_ext);
+	if (ret)
+		return ret;
 
 	*reg_val = 0;
-	if (__riscv_isa_extension_available(vcpu->arch.isa, host_isa_ext))
+	if (__riscv_isa_extension_available(vcpu->arch.isa, guest_ext))
 		*reg_val = 1; /* Mark the given extension as available */
 
 	return 0;
@@ -657,17 +683,14 @@ static int riscv_vcpu_set_isa_ext_single(struct kvm_vcpu *vcpu,
 					 unsigned long reg_num,
 					 unsigned long reg_val)
 {
-	unsigned long host_isa_ext;
-
-	if (reg_num >= KVM_RISCV_ISA_EXT_MAX ||
-	    reg_num >= ARRAY_SIZE(kvm_isa_ext_arr))
-		return -ENOENT;
+	unsigned long guest_ext;
+	int ret;
 
-	host_isa_ext = kvm_isa_ext_arr[reg_num];
-	if (!__riscv_isa_extension_available(NULL, host_isa_ext))
-		return -ENOENT;
+	ret = kvm_riscv_vcpu_isa_check_host(reg_num, &guest_ext);
+	if (ret)
+		return ret;
 
-	if (reg_val == test_bit(host_isa_ext, vcpu->arch.isa))
+	if (reg_val == test_bit(guest_ext, vcpu->arch.isa))
 		return 0;
 
 	if (!vcpu->arch.ran_atleast_once) {
@@ -677,10 +700,10 @@ static int riscv_vcpu_set_isa_ext_single(struct kvm_vcpu *vcpu,
 		 */
 		if (reg_val == 1 &&
 		    kvm_riscv_vcpu_isa_enable_allowed(reg_num))
-			set_bit(host_isa_ext, vcpu->arch.isa);
+			set_bit(guest_ext, vcpu->arch.isa);
 		else if (!reg_val &&
 			 kvm_riscv_vcpu_isa_disable_allowed(reg_num))
-			clear_bit(host_isa_ext, vcpu->arch.isa);
+			clear_bit(guest_ext, vcpu->arch.isa);
 		else
 			return -EINVAL;
 		kvm_riscv_vcpu_fp_reset(vcpu);
@@ -1041,16 +1064,15 @@ static int copy_fp_d_reg_indices(const struct kvm_vcpu *vcpu,
 static int copy_isa_ext_reg_indices(const struct kvm_vcpu *vcpu,
 				u64 __user *uindices)
 {
+	unsigned long guest_ext;
 	unsigned int n = 0;
-	unsigned long isa_ext;
 
 	for (int i = 0; i < KVM_RISCV_ISA_EXT_MAX; i++) {
 		u64 size = IS_ENABLED(CONFIG_32BIT) ?
 			   KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
 		u64 reg = KVM_REG_RISCV | size | KVM_REG_RISCV_ISA_EXT | i;
 
-		isa_ext = kvm_isa_ext_arr[i];
-		if (!__riscv_isa_extension_available(NULL, isa_ext))
+		if (kvm_riscv_vcpu_isa_check_host(i, &guest_ext))
 			continue;
 
 		if (uindices) {
@@ -1070,66 +1092,14 @@ static inline unsigned long num_isa_ext_regs(const struct kvm_vcpu *vcpu)
 	return copy_isa_ext_reg_indices(vcpu, NULL);;
 }
 
-static int copy_sbi_ext_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
-{
-	unsigned int n = 0;
-
-	for (int i = 0; i < KVM_RISCV_SBI_EXT_MAX; i++) {
-		u64 size = IS_ENABLED(CONFIG_32BIT) ?
-			   KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
-		u64 reg = KVM_REG_RISCV | size | KVM_REG_RISCV_SBI_EXT |
-			  KVM_REG_RISCV_SBI_SINGLE | i;
-
-		if (!riscv_vcpu_supports_sbi_ext(vcpu, i))
-			continue;
-
-		if (uindices) {
-			if (put_user(reg, uindices))
-				return -EFAULT;
-			uindices++;
-		}
-
-		n++;
-	}
-
-	return n;
-}
-
 static unsigned long num_sbi_ext_regs(struct kvm_vcpu *vcpu)
 {
-	return copy_sbi_ext_reg_indices(vcpu, NULL);
-}
-
-static int copy_sbi_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
-{
-	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
-	int total = 0;
-
-	if (scontext->ext_status[KVM_RISCV_SBI_EXT_STA] == KVM_RISCV_SBI_EXT_STATUS_ENABLED) {
-		u64 size = IS_ENABLED(CONFIG_32BIT) ? KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
-		int n = sizeof(struct kvm_riscv_sbi_sta) / sizeof(unsigned long);
-
-		for (int i = 0; i < n; i++) {
-			u64 reg = KVM_REG_RISCV | size |
-				  KVM_REG_RISCV_SBI_STATE |
-				  KVM_REG_RISCV_SBI_STA | i;
-
-			if (uindices) {
-				if (put_user(reg, uindices))
-					return -EFAULT;
-				uindices++;
-			}
-		}
-
-		total += n;
-	}
-
-	return total;
+	return kvm_riscv_vcpu_reg_indices_sbi_ext(vcpu, NULL);
 }
 
 static inline unsigned long num_sbi_regs(struct kvm_vcpu *vcpu)
 {
-	return copy_sbi_reg_indices(vcpu, NULL);
+	return kvm_riscv_vcpu_reg_indices_sbi(vcpu, NULL);
 }
 
 static inline unsigned long num_vector_regs(const struct kvm_vcpu *vcpu)
@@ -1252,12 +1222,12 @@ int kvm_riscv_vcpu_copy_reg_indices(struct kvm_vcpu *vcpu,
 		return ret;
 	uindices += ret;
 
-	ret = copy_sbi_ext_reg_indices(vcpu, uindices);
+	ret = kvm_riscv_vcpu_reg_indices_sbi_ext(vcpu, uindices);
 	if (ret < 0)
 		return ret;
 	uindices += ret;
 
-	ret = copy_sbi_reg_indices(vcpu, uindices);
+	ret = kvm_riscv_vcpu_reg_indices_sbi(vcpu, uindices);
 	if (ret < 0)
 		return ret;
 	uindices += ret;