From a8a32dd460a1d838cfe97ec53a2eb76c018c5dbf Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 22 Jul 2019 18:22:19 +0100 Subject: [PATCH 38/39] target/i386: skip KVM_GET/SET_NESTED_STATE if VMX disabled, or for SVM RH-Author: Paolo Bonzini Message-id: <20190722182220.19374-18-pbonzini@redhat.com> Patchwork-id: 89636 O-Subject: [RHEL-8.1.0 PATCH qemu-kvm v3 17/18] target/i386: skip KVM_GET/SET_NESTED_STATE if VMX disabled, or for SVM Bugzilla: 1689269 RH-Acked-by: Peter Xu RH-Acked-by: Laurent Vivier RH-Acked-by: Dr. David Alan Gilbert Do not allocate env->nested_state unless we later need to migrate the nested virtualization state. With this change, nested_state_needed() will return false if the VMX flag is not included in the virtual machine. KVM_GET/SET_NESTED_STATE is also disabled for SVM which is safer (we know that at least the NPT root and paging mode have to be saved/loaded), and thus the corresponding subsection can go away as well. Inspired by a patch from Liran Alon. Signed-off-by: Paolo Bonzini (cherry picked from commit 1e44f3ab71fb4291d266a264f7c207ae5c6d59b2) Signed-off-by: Danilo C. L. de Paula --- target/i386/kvm.c | 16 ++++++++-------- target/i386/machine.c | 21 +-------------------- 2 files changed, 9 insertions(+), 28 deletions(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 0bd286e..8648f1f 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -1220,15 +1220,15 @@ int kvm_arch_init_vcpu(CPUState *cs) max_nested_state_len = kvm_max_nested_state_length(); if (max_nested_state_len > 0) { assert(max_nested_state_len >= offsetof(struct kvm_nested_state, data)); - env->nested_state = g_malloc0(max_nested_state_len); - env->nested_state->size = max_nested_state_len; - - if (IS_INTEL_CPU(env)) { - struct kvm_vmx_nested_state_hdr *vmx_hdr = - &env->nested_state->hdr.vmx; + if (cpu_has_vmx(env)) { + struct kvm_vmx_nested_state_hdr *vmx_hdr; + env->nested_state = g_malloc0(max_nested_state_len); + env->nested_state->size = max_nested_state_len; env->nested_state->format = KVM_STATE_NESTED_FORMAT_VMX; + + vmx_hdr = &env->nested_state->hdr.vmx; vmx_hdr->vmxon_pa = -1ull; vmx_hdr->vmcs12_pa = -1ull; } @@ -2966,7 +2966,7 @@ static int kvm_put_nested_state(X86CPU *cpu) CPUX86State *env = &cpu->env; int max_nested_state_len = kvm_max_nested_state_length(); - if (max_nested_state_len <= 0) { + if (!env->nested_state) { return 0; } @@ -2980,7 +2980,7 @@ static int kvm_get_nested_state(X86CPU *cpu) int max_nested_state_len = kvm_max_nested_state_length(); int ret; - if (max_nested_state_len <= 0) { + if (!env->nested_state) { return 0; } diff --git a/target/i386/machine.c b/target/i386/machine.c index 8d90d98..fa8d1cc 100644 --- a/target/i386/machine.c +++ b/target/i386/machine.c @@ -1004,31 +1004,13 @@ static const VMStateDescription vmstate_vmx_nested_state = { } }; -static bool svm_nested_state_needed(void *opaque) -{ - struct kvm_nested_state *nested_state = opaque; - - return (nested_state->format == KVM_STATE_NESTED_FORMAT_SVM); -} - -static const VMStateDescription vmstate_svm_nested_state = { - .name = "cpu/kvm_nested_state/svm", - .version_id = 1, - .minimum_version_id = 1, - .needed = svm_nested_state_needed, - .fields = (VMStateField[]) { - VMSTATE_END_OF_LIST() - } -}; - static bool nested_state_needed(void *opaque) { X86CPU *cpu = opaque; CPUX86State *env = &cpu->env; return (env->nested_state && - (vmx_nested_state_needed(env->nested_state) || - svm_nested_state_needed(env->nested_state))); + vmx_nested_state_needed(env->nested_state)); } static int nested_state_post_load(void *opaque, int version_id) @@ -1090,7 +1072,6 @@ static const VMStateDescription vmstate_kvm_nested_state = { }, .subsections = (const VMStateDescription*[]) { &vmstate_vmx_nested_state, - &vmstate_svm_nested_state, NULL } }; -- 1.8.3.1