From: Anup Patel <apatel@ventanamicro.com>
To: Atish Patra <atish.patra@linux.dev>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Alexandre Ghiti <alex@ghiti.fr>,
Andrew Jones <ajones@ventanamicro.com>,
Anup Patel <anup@brainfault.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Shuah Khan <shuah@kernel.org>,
kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH 3/6] RISC-V: KVM: Introduce optional ONE_REG callbacks for SBI extensions
Date: Thu, 14 Aug 2025 21:25:45 +0530 [thread overview]
Message-ID: <20250814155548.457172-4-apatel@ventanamicro.com> (raw)
In-Reply-To: <20250814155548.457172-1-apatel@ventanamicro.com>
SBI extensions can have per-VCPU state which needs to be saved/restored
through ONE_REG interface for Guest/VM migration. Introduce optional
ONE_REG callbacks for SBI extensions so that ONE_REG implementation
for an SBI extenion is part of the extension sources.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
arch/riscv/include/asm/kvm_vcpu_sbi.h | 21 ++--
arch/riscv/kvm/vcpu_onereg.c | 31 +-----
arch/riscv/kvm/vcpu_sbi.c | 145 ++++++++++++++++++++++----
arch/riscv/kvm/vcpu_sbi_sta.c | 64 ++++++++----
4 files changed, 178 insertions(+), 83 deletions(-)
diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index 766031e80960..144c3f6d5eb9 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -59,6 +59,15 @@ struct kvm_vcpu_sbi_extension {
void (*deinit)(struct kvm_vcpu *vcpu);
void (*reset)(struct kvm_vcpu *vcpu);
+
+ bool have_state;
+ 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);
@@ -73,10 +82,9 @@ 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);
@@ -85,11 +93,6 @@ 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
diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
index b77748a56a59..5843b0519224 100644
--- a/arch/riscv/kvm/vcpu_onereg.c
+++ b/arch/riscv/kvm/vcpu_onereg.c
@@ -1090,36 +1090,9 @@ 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;
-}
-
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)
@@ -1247,7 +1220,7 @@ int kvm_riscv_vcpu_copy_reg_indices(struct kvm_vcpu *vcpu,
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;
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 01a93f4fdb16..8b3c393e0c83 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -364,64 +364,163 @@ int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
return 0;
}
-int kvm_riscv_vcpu_set_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)
+{
+ 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;
+ unsigned long state_reg_count;
+ int i, j, rc, count = 0;
+ u64 reg;
+
+ for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+ entry = &sbi_ext[i];
+ ext = entry->ext_ptr;
+
+ if (!ext->have_state ||
+ scontext->ext_status[entry->ext_idx] != KVM_RISCV_SBI_EXT_STATUS_ENABLED)
+ continue;
+
+ state_reg_count = ext->get_state_reg_count(vcpu);
+ if (!uindices)
+ goto skip_put_user;
+
+ for (j = 0; j < state_reg_count; j++) {
+ if (ext->get_state_reg_id) {
+ rc = ext->get_state_reg_id(vcpu, j, ®);
+ if (rc)
+ return rc;
+ } else {
+ reg = KVM_REG_RISCV |
+ (IS_ENABLED(CONFIG_32BIT) ?
+ KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64) |
+ KVM_REG_RISCV_SBI_STATE |
+ ext->state_reg_subtype | j;
+ }
+
+ if (put_user(reg, uindices))
+ return -EFAULT;
+ uindices++;
+ }
+
+skip_put_user:
+ count += state_reg_count;
+ }
+
+ return count;
+}
+
+static const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext_withstate(struct kvm_vcpu *vcpu,
+ unsigned long subtype)
+{
+ 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 i;
+
+ for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+ entry = &sbi_ext[i];
+ ext = entry->ext_ptr;
+
+ if (ext->have_state &&
+ ext->state_reg_subtype == subtype &&
+ scontext->ext_status[entry->ext_idx] == KVM_RISCV_SBI_EXT_STATUS_ENABLED)
+ return ext;
+ }
+
+ return NULL;
+}
+
+int kvm_riscv_vcpu_set_reg_sbi(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
unsigned long __user *uaddr =
(unsigned long __user *)(unsigned long)reg->addr;
unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
KVM_REG_SIZE_MASK |
KVM_REG_RISCV_SBI_STATE);
- unsigned long reg_subtype, reg_val;
-
- if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ const struct kvm_vcpu_sbi_extension *ext;
+ unsigned long reg_subtype;
+ void *reg_val;
+ u64 data64;
+ u32 data32;
+ u16 data16;
+ u8 data8;
+
+ switch (KVM_REG_SIZE(reg->id)) {
+ case 1:
+ reg_val = &data8;
+ break;
+ case 2:
+ reg_val = &data16;
+ break;
+ case 4:
+ reg_val = &data32;
+ break;
+ case 8:
+ reg_val = &data64;
+ break;
+ default:
return -EINVAL;
+ };
- if (copy_from_user(®_val, uaddr, KVM_REG_SIZE(reg->id)))
+ if (copy_from_user(reg_val, uaddr, KVM_REG_SIZE(reg->id)))
return -EFAULT;
reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;
- switch (reg_subtype) {
- case KVM_REG_RISCV_SBI_STA:
- return kvm_riscv_vcpu_set_reg_sbi_sta(vcpu, reg_num, reg_val);
- default:
+ ext = kvm_vcpu_sbi_find_ext_withstate(vcpu, reg_subtype);
+ if (!ext || !ext->set_state_reg)
return -EINVAL;
- }
- return 0;
+ return ext->set_state_reg(vcpu, reg_num, KVM_REG_SIZE(reg->id), reg_val);
}
-int kvm_riscv_vcpu_get_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)
{
unsigned long __user *uaddr =
(unsigned long __user *)(unsigned long)reg->addr;
unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
KVM_REG_SIZE_MASK |
KVM_REG_RISCV_SBI_STATE);
- unsigned long reg_subtype, reg_val;
+ const struct kvm_vcpu_sbi_extension *ext;
+ unsigned long reg_subtype;
+ void *reg_val;
+ u64 data64;
+ u32 data32;
+ u16 data16;
+ u8 data8;
int ret;
- if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ switch (KVM_REG_SIZE(reg->id)) {
+ case 1:
+ reg_val = &data8;
+ break;
+ case 2:
+ reg_val = &data16;
+ break;
+ case 4:
+ reg_val = &data32;
+ break;
+ case 8:
+ reg_val = &data64;
+ break;
+ default:
return -EINVAL;
+ };
reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;
- switch (reg_subtype) {
- case KVM_REG_RISCV_SBI_STA:
- ret = kvm_riscv_vcpu_get_reg_sbi_sta(vcpu, reg_num, ®_val);
- break;
- default:
+ ext = kvm_vcpu_sbi_find_ext_withstate(vcpu, reg_subtype);
+ if (!ext || !ext->get_state_reg)
return -EINVAL;
- }
+ ret = ext->get_state_reg(vcpu, reg_num, KVM_REG_SIZE(reg->id), reg_val);
if (ret)
return ret;
- if (copy_to_user(uaddr, ®_val, KVM_REG_SIZE(reg->id)))
+ if (copy_to_user(uaddr, reg_val, KVM_REG_SIZE(reg->id)))
return -EFAULT;
return 0;
diff --git a/arch/riscv/kvm/vcpu_sbi_sta.c b/arch/riscv/kvm/vcpu_sbi_sta.c
index cc6cb7c8f0e4..d14cf6255d83 100644
--- a/arch/riscv/kvm/vcpu_sbi_sta.c
+++ b/arch/riscv/kvm/vcpu_sbi_sta.c
@@ -151,63 +151,83 @@ static unsigned long kvm_sbi_ext_sta_probe(struct kvm_vcpu *vcpu)
return !!sched_info_on();
}
-const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta = {
- .extid_start = 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,
-};
+static unsigned long kvm_sbi_ext_sta_get_state_reg_count(struct kvm_vcpu *vcpu)
+{
+ return sizeof(struct kvm_riscv_sbi_sta) / sizeof(unsigned long);
+}
-int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu,
- unsigned long reg_num,
- unsigned long *reg_val)
+static int kvm_sbi_ext_sta_get_reg(struct kvm_vcpu *vcpu, unsigned long reg_num,
+ unsigned long reg_size, void *reg_val)
{
+ unsigned long *value;
+
+ if (reg_size != sizeof(unsigned long))
+ return -EINVAL;
+ value = reg_val;
+
switch (reg_num) {
case KVM_REG_RISCV_SBI_STA_REG(shmem_lo):
- *reg_val = (unsigned long)vcpu->arch.sta.shmem;
+ *value = (unsigned long)vcpu->arch.sta.shmem;
break;
case KVM_REG_RISCV_SBI_STA_REG(shmem_hi):
if (IS_ENABLED(CONFIG_32BIT))
- *reg_val = upper_32_bits(vcpu->arch.sta.shmem);
+ *value = upper_32_bits(vcpu->arch.sta.shmem);
else
- *reg_val = 0;
+ *value = 0;
break;
default:
- return -EINVAL;
+ return -ENOENT;
}
return 0;
}
-int kvm_riscv_vcpu_set_reg_sbi_sta(struct kvm_vcpu *vcpu,
- unsigned long reg_num,
- unsigned long reg_val)
+static int kvm_sbi_ext_sta_set_reg(struct kvm_vcpu *vcpu, unsigned long reg_num,
+ unsigned long reg_size, const void *reg_val)
{
+ unsigned long value;
+
+ if (reg_size != sizeof(unsigned long))
+ return -EINVAL;
+ value = *(const unsigned long *)reg_val;
+
switch (reg_num) {
case KVM_REG_RISCV_SBI_STA_REG(shmem_lo):
if (IS_ENABLED(CONFIG_32BIT)) {
gpa_t hi = upper_32_bits(vcpu->arch.sta.shmem);
- vcpu->arch.sta.shmem = reg_val;
+ vcpu->arch.sta.shmem = value;
vcpu->arch.sta.shmem |= hi << 32;
} else {
- vcpu->arch.sta.shmem = reg_val;
+ vcpu->arch.sta.shmem = value;
}
break;
case KVM_REG_RISCV_SBI_STA_REG(shmem_hi):
if (IS_ENABLED(CONFIG_32BIT)) {
gpa_t lo = lower_32_bits(vcpu->arch.sta.shmem);
- vcpu->arch.sta.shmem = ((gpa_t)reg_val << 32);
+ vcpu->arch.sta.shmem = ((gpa_t)value << 32);
vcpu->arch.sta.shmem |= lo;
- } else if (reg_val != 0) {
+ } else if (value != 0) {
return -EINVAL;
}
break;
default:
- return -EINVAL;
+ return -ENOENT;
}
return 0;
}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta = {
+ .extid_start = 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,
+ .have_state = true,
+ .state_reg_subtype = KVM_REG_RISCV_SBI_STA,
+ .get_state_reg_count = kvm_sbi_ext_sta_get_state_reg_count,
+ .get_state_reg = kvm_sbi_ext_sta_get_reg,
+ .set_state_reg = kvm_sbi_ext_sta_set_reg,
+};
--
2.43.0
next prev parent reply other threads:[~2025-08-14 15:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-14 15:55 [PATCH 0/6] ONE_REG interface for SBI FWFT extension Anup Patel
2025-08-14 15:55 ` [PATCH 1/6] RISC-V: KVM: Set initial value of hedeleg in kvm_arch_vcpu_create() Anup Patel
2025-08-15 20:04 ` Andrew Jones
2025-08-19 9:01 ` Nutty.Liu
2025-08-14 15:55 ` [PATCH 2/6] RISC-V: KVM: Introduce feature specific reset for SBI FWFT Anup Patel
2025-08-15 20:14 ` Andrew Jones
2025-08-19 9:02 ` Nutty.Liu
2025-08-14 15:55 ` Anup Patel [this message]
2025-08-15 21:00 ` [PATCH 3/6] RISC-V: KVM: Introduce optional ONE_REG callbacks for SBI extensions Andrew Jones
2025-08-17 12:04 ` Anup Patel
2025-08-14 15:55 ` [PATCH 4/6] RISC-V: KVM: Move copy_sbi_ext_reg_indices() to SBI implementation Anup Patel
2025-08-15 21:04 ` Andrew Jones
2025-08-14 15:55 ` [PATCH 5/6] RISC-V: KVM: Implement ONE_REG interface for SBI FWFT state Anup Patel
2025-08-14 15:55 ` [PATCH 6/6] KVM: riscv: selftests: Add SBI FWFT to get-reg-list test Anup Patel
2025-08-18 10:29 ` [PATCH 0/6] ONE_REG interface for SBI FWFT extension Radim Krčmář
2025-08-19 6:30 ` Anup Patel
2025-08-19 11:43 ` Radim Krčmář
2025-08-19 15:52 ` Anup Patel
2025-08-19 17:35 ` Radim Krčmář
2025-08-21 6:26 ` Anup Patel
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