[PATCH v5 66/69] KVM: arm64: nv: Allocate VNCR page when required
From: Marc Zyngier <maz@kernel.org>
Date: 2021-11-29 20:37:51
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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@kernel.org> --- 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
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