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-rw-r--r--arch/arm64/include/asm/kvm_host.h1
-rw-r--r--arch/arm64/include/asm/sysreg.h3
-rw-r--r--arch/arm64/kvm/fpsimd.c9
-rw-r--r--arch/arm64/kvm/hyp/switch.c3
-rw-r--r--arch/arm64/kvm/sys_regs.c83
5 files changed, 93 insertions, 6 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index ad4f7f004498..22cf484b561f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -121,6 +121,7 @@ enum vcpu_sysreg {
SCTLR_EL1, /* System Control Register */
ACTLR_EL1, /* Auxiliary Control Register */
CPACR_EL1, /* Coprocessor Access Control */
+ ZCR_EL1, /* SVE Control */
TTBR0_EL1, /* Translation Table Base Register 0 */
TTBR1_EL1, /* Translation Table Base Register 1 */
TCR_EL1, /* Translation Control Register */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 5b267dec6194..4d6262df79bb 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -454,6 +454,9 @@
#define SYS_ICH_LR14_EL2 __SYS__LR8_EL2(6)
#define SYS_ICH_LR15_EL2 __SYS__LR8_EL2(7)
+/* VHE encodings for architectural EL0/1 system registers */
+#define SYS_ZCR_EL12 sys_reg(3, 5, 1, 2, 0)
+
/* Common SCTLR_ELx flags. */
#define SCTLR_ELx_DSSBS (_BITUL(44))
#define SCTLR_ELx_ENIA (_BITUL(31))
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 1cf4f0269471..7053bf402131 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -103,14 +103,21 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
{
unsigned long flags;
+ bool host_has_sve = system_supports_sve();
+ bool guest_has_sve = vcpu_has_sve(vcpu);
local_irq_save(flags);
if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
+ u64 *guest_zcr = &vcpu->arch.ctxt.sys_regs[ZCR_EL1];
+
/* Clean guest FP state to memory and invalidate cpu view */
fpsimd_save();
fpsimd_flush_cpu_state();
- } else if (system_supports_sve()) {
+
+ if (guest_has_sve)
+ *guest_zcr = read_sysreg_s(SYS_ZCR_EL12);
+ } else if (host_has_sve) {
/*
* The FPSIMD/SVE state in the CPU has not been touched, and we
* have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 3563fe655cd5..9d46066276b9 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -351,6 +351,9 @@ static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu)
__fpsimd_restore_state(&vcpu->arch.ctxt.gp_regs.fp_regs);
+ if (vcpu_has_sve(vcpu))
+ write_sysreg_s(vcpu->arch.ctxt.sys_regs[ZCR_EL1], SYS_ZCR_EL12);
+
/* Skip restoring fpexc32 for AArch64 guests */
if (!(read_sysreg(hcr_el2) & HCR_RW))
write_sysreg(vcpu->arch.ctxt.sys_regs[FPEXC32_EL2],
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c86a7b0d3e6b..09e9b0625911 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1051,10 +1051,7 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
- if (id == SYS_ID_AA64PFR0_EL1) {
- if (val & (0xfUL << ID_AA64PFR0_SVE_SHIFT))
- kvm_debug("SVE unsupported for guests, suppressing\n");
-
+ if (id == SYS_ID_AA64PFR0_EL1 && !vcpu_has_sve(vcpu)) {
val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
} else if (id == SYS_ID_AA64ISAR1_EL1) {
const u64 ptrauth_mask = (0xfUL << ID_AA64ISAR1_APA_SHIFT) |
@@ -1101,6 +1098,81 @@ static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
+/* Visibility overrides for SVE-specific control registers */
+static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
+ const struct sys_reg_desc *rd)
+{
+ if (vcpu_has_sve(vcpu))
+ return 0;
+
+ return REG_HIDDEN_USER | REG_HIDDEN_GUEST;
+}
+
+/* Visibility overrides for SVE-specific ID registers */
+static unsigned int sve_id_visibility(const struct kvm_vcpu *vcpu,
+ const struct sys_reg_desc *rd)
+{
+ if (vcpu_has_sve(vcpu))
+ return 0;
+
+ return REG_HIDDEN_USER;
+}
+
+/* Generate the emulated ID_AA64ZFR0_EL1 value exposed to the guest */
+static u64 guest_id_aa64zfr0_el1(const struct kvm_vcpu *vcpu)
+{
+ if (!vcpu_has_sve(vcpu))
+ return 0;
+
+ return read_sanitised_ftr_reg(SYS_ID_AA64ZFR0_EL1);
+}
+
+static bool access_id_aa64zfr0_el1(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *rd)
+{
+ if (p->is_write)
+ return write_to_read_only(vcpu, p, rd);
+
+ p->regval = guest_id_aa64zfr0_el1(vcpu);
+ return true;
+}
+
+static int get_id_aa64zfr0_el1(struct kvm_vcpu *vcpu,
+ const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ u64 val;
+
+ if (!vcpu_has_sve(vcpu))
+ return -ENOENT;
+
+ val = guest_id_aa64zfr0_el1(vcpu);
+ return reg_to_user(uaddr, &val, reg->id);
+}
+
+static int set_id_aa64zfr0_el1(struct kvm_vcpu *vcpu,
+ const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ const u64 id = sys_reg_to_index(rd);
+ int err;
+ u64 val;
+
+ if (!vcpu_has_sve(vcpu))
+ return -ENOENT;
+
+ err = reg_from_user(&val, uaddr, id);
+ if (err)
+ return err;
+
+ /* This is what we mean by invariant: you can't change it. */
+ if (val != guest_id_aa64zfr0_el1(vcpu))
+ return -EINVAL;
+
+ return 0;
+}
+
/*
* cpufeature ID register user accessors
*
@@ -1346,7 +1418,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
ID_SANITISED(ID_AA64PFR1_EL1),
ID_UNALLOCATED(4,2),
ID_UNALLOCATED(4,3),
- ID_UNALLOCATED(4,4),
+ { SYS_DESC(SYS_ID_AA64ZFR0_EL1), access_id_aa64zfr0_el1, .get_user = get_id_aa64zfr0_el1, .set_user = set_id_aa64zfr0_el1, .visibility = sve_id_visibility },
ID_UNALLOCATED(4,5),
ID_UNALLOCATED(4,6),
ID_UNALLOCATED(4,7),
@@ -1383,6 +1455,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
{ SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },
+ { SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
{ SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
{ SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
{ SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 },