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 <[email protected]> --- arch/arm64/include/asm/kvm_host.h | 3 ++- arch/arm64/kvm/nested.c | 8 ++++++++ arch/arm64/kvm/reset.c | 1 + 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 657c2c5d1a39..a26ab0fda1a7 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -526,7 +526,8 @@ 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_const_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 6adff9b433e0..58873e4c85cb 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -47,6 +47,12 @@ int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu) if (!cpus_have_const_cap(ARM64_HAS_NESTED_VIRT)) return -EINVAL; + if (cpus_have_const_cap(ARM64_HAS_ENHANCED_NESTED_VIRT)) { + 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); /* @@ -64,6 +70,8 @@ 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 07462af1b69d..ce8d8f53fcd0 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -207,6 +207,7 @@ 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) -- 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
