As a placeholder while SME guests were not supported we provide a u64 in
struct kvm_vcpu_arch for the host kernel's floating point save code to use
when managing KVM guests. In order to support KVM guests we will need to
replace this with a proper KVM system register, do so and update the system
register definition to make it accessible to the guest if it has SME.
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/kvm/fpsimd.c | 8 +++++---
arch/arm64/kvm/sys_regs.c | 2 +-
3 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 36bf9d7e92e1..690c439b5e2a 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -356,6 +356,7 @@ enum vcpu_sysreg {
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
OSLSR_EL1, /* OS Lock Status Register */
DISR_EL1, /* Deferred Interrupt Status Register */
+ SVCR, /* Scalable Vector Control Register */
/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
@@ -518,7 +519,6 @@ struct kvm_vcpu_arch {
void *sve_state;
enum fp_type fp_type;
unsigned int max_vl[ARM64_VEC_MAX];
- u64 svcr;
/* Stage 2 paging state used by the hardware on next switch */
struct kvm_s2_mmu *hw_mmu;
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index a402a072786a..1be18d719fce 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -145,14 +145,16 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) {
/*
- * Currently we do not support SME guests so SVCR is
- * always 0 and we just need a variable to point to.
+ * We peer into the registers since SVCR is saved as
+ * part of the floating point state, determining which
+ * registers exist and their size, so is saved by
+ * fpsimd_save().
*/
fp_state.st = &vcpu->arch.ctxt.fp_regs;
fp_state.sve_state = vcpu->arch.sve_state;
fp_state.sve_vl = vcpu->arch.max_vl[ARM64_VEC_SVE];
fp_state.sme_state = NULL;
- fp_state.svcr = &vcpu->arch.svcr;
+ fp_state.svcr = &(vcpu->arch.ctxt.sys_regs[SVCR]);
fp_state.fp_type = &vcpu->arch.fp_type;
if (vcpu_has_sve(vcpu))
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index b618bcab526e..f908aa3fb606 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2336,7 +2336,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
.get_user = get_id_reg, .visibility = sme_visibility },
{ SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
{ SYS_DESC(SYS_CTR_EL0), access_ctr },
- { SYS_DESC(SYS_SVCR), undef_access },
+ { SYS_DESC(SYS_SVCR), NULL, reset_val, SVCR, 0, .visibility = sme_visibility },
{ PMU_SYS_REG(PMCR_EL0), .access = access_pmcr, .reset = reset_pmcr,
.reg = PMCR_EL0, .get_user = get_pmcr, .set_user = set_pmcr },
--
2.30.2
