If running a NV guest on an ARMv8.4-NV capable system, let's
allocate an additional page that will be used by the hypervisor
to fulfill system register accesses.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 3 ++-
arch/arm64/kvm/nested.c | 10 ++++++++++
arch/arm64/kvm/reset.c | 1 +
3 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c21551551ddf..595516450637 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -575,7 +575,8 @@ struct kvm_vcpu_arch {
*/
static inline u64 *__ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r)
{
- if (unlikely(r >= __VNCR_START__ && ctxt->vncr_array))
+ if (unlikely(cpus_have_final_cap(ARM64_HAS_ENHANCED_NESTED_VIRT) &&
+ r >= __VNCR_START__ && ctxt->vncr_array))
return &ctxt->vncr_array[r - __VNCR_START__];
return (u64 *)&ctxt->sys_regs[r];
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index e11bdee15df2..7c9dd1edf011 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -47,6 +47,14 @@ int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu)
if (!cpus_have_final_cap(ARM64_HAS_NESTED_VIRT))
return -EINVAL;
+ if (cpus_have_final_cap(ARM64_HAS_ENHANCED_NESTED_VIRT)) {
+ if (!vcpu->arch.ctxt.vncr_array)
+ vcpu->arch.ctxt.vncr_array = (u64 *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+
+ if (!vcpu->arch.ctxt.vncr_array)
+ return -ENOMEM;
+ }
+
mutex_lock(&kvm->lock);
/*
@@ -76,6 +84,8 @@ int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu)
kvm_init_stage2_mmu(kvm, &tmp[num_mmus - 2])) {
kvm_free_stage2_pgd(&tmp[num_mmus - 1]);
kvm_free_stage2_pgd(&tmp[num_mmus - 2]);
+ free_page((unsigned long)vcpu->arch.ctxt.vncr_array);
+ vcpu->arch.ctxt.vncr_array = NULL;
} else {
kvm->arch.nested_mmus_size = num_mmus;
ret = 0;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 38a7182819fb..9f580241b0bd 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -146,6 +146,7 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu)
void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
kfree(vcpu->arch.sve_state);
+ free_page((unsigned long)vcpu->arch.ctxt.vncr_array);
}
static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)
--
2.30.2
