Blame SOURCES/kvm-target-i386-skip-KVM_GET-SET_NESTED_STATE-if-VMX-dis.patch

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