summaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/vmx.c
diff options
context:
space:
mode:
authorPaolo Bonzini2018-07-18 18:49:01 +0200
committerPaolo Bonzini2018-08-06 17:57:58 +0200
commit7f7f1ba33cf2c21d001821313088c231db42ff40 (patch)
treeeed46700a5932890c27f8770f244c9bdb21527fc /arch/x86/kvm/vmx.c
parentkvm: selftests: add basic test for state save and restore (diff)
downloadkernel-qcow2-linux-7f7f1ba33cf2c21d001821313088c231db42ff40.tar.gz
kernel-qcow2-linux-7f7f1ba33cf2c21d001821313088c231db42ff40.tar.xz
kernel-qcow2-linux-7f7f1ba33cf2c21d001821313088c231db42ff40.zip
KVM: x86: do not load vmcs12 pages while still in SMM
If the vCPU enters system management mode while running a nested guest, RSM starts processing the vmentry while still in SMM. In that case, however, the pages pointed to by the vmcs12 might be incorrectly loaded from SMRAM. To avoid this, delay the handling of the pages until just before the next vmentry. This is done with a new request and a new entry in kvm_x86_ops, which we will be able to reuse for nested VMX state migration. Extracted from a patch by Jim Mattson and KarimAllah Ahmed. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
-rw-r--r--arch/x86/kvm/vmx.c54
1 files changed, 36 insertions, 18 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6318167b1464..fee44e4c5c79 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10660,9 +10660,9 @@ static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
struct vmcs12 *vmcs12);
-static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
- struct vmcs12 *vmcs12)
+static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
{
+ struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct page *page;
u64 hpa;
@@ -11774,12 +11774,17 @@ static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
return 0;
}
-static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu)
+/*
+ * If exit_qual is NULL, this is being called from RSM.
+ * Otherwise it's called from vmlaunch/vmresume.
+ */
+static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
- u32 exit_qual;
- int r;
+ bool from_vmentry = !!exit_qual;
+ u32 dummy_exit_qual;
+ int r = 0;
enter_guest_mode(vcpu);
@@ -11793,17 +11798,28 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu)
vcpu->arch.tsc_offset += vmcs12->tsc_offset;
r = EXIT_REASON_INVALID_STATE;
- if (prepare_vmcs02(vcpu, vmcs12, &exit_qual))
+ if (prepare_vmcs02(vcpu, vmcs12, from_vmentry ? exit_qual : &dummy_exit_qual))
goto fail;
- nested_get_vmcs12_pages(vcpu, vmcs12);
+ if (from_vmentry) {
+ nested_get_vmcs12_pages(vcpu);
- r = EXIT_REASON_MSR_LOAD_FAIL;
- exit_qual = nested_vmx_load_msr(vcpu,
- vmcs12->vm_entry_msr_load_addr,
- vmcs12->vm_entry_msr_load_count);
- if (exit_qual)
- goto fail;
+ r = EXIT_REASON_MSR_LOAD_FAIL;
+ *exit_qual = nested_vmx_load_msr(vcpu,
+ vmcs12->vm_entry_msr_load_addr,
+ vmcs12->vm_entry_msr_load_count);
+ if (*exit_qual)
+ goto fail;
+ } else {
+ /*
+ * The MMU is not initialized to point at the right entities yet and
+ * "get pages" would need to read data from the guest (i.e. we will
+ * need to perform gpa to hpa translation). Request a call
+ * to nested_get_vmcs12_pages before the next VM-entry. The MSRs
+ * have already been set at vmentry time and should not be reset.
+ */
+ kvm_make_request(KVM_REQ_GET_VMCS12_PAGES, vcpu);
+ }
/*
* Note no nested_vmx_succeed or nested_vmx_fail here. At this point
@@ -11818,8 +11834,7 @@ fail:
vcpu->arch.tsc_offset -= vmcs12->tsc_offset;
leave_guest_mode(vcpu);
vmx_switch_vmcs(vcpu, &vmx->vmcs01);
- nested_vmx_entry_failure(vcpu, vmcs12, r, exit_qual);
- return 1;
+ return r;
}
/*
@@ -11896,10 +11911,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
*/
vmx->nested.nested_run_pending = 1;
- ret = enter_vmx_non_root_mode(vcpu);
+ ret = enter_vmx_non_root_mode(vcpu, &exit_qual);
if (ret) {
+ nested_vmx_entry_failure(vcpu, vmcs12, ret, exit_qual);
vmx->nested.nested_run_pending = 0;
- return ret;
+ return 1;
}
/*
@@ -12985,7 +13001,7 @@ static int vmx_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase)
if (vmx->nested.smm.guest_mode) {
vcpu->arch.hflags &= ~HF_SMM_MASK;
- ret = enter_vmx_non_root_mode(vcpu);
+ ret = enter_vmx_non_root_mode(vcpu, NULL);
vcpu->arch.hflags |= HF_SMM_MASK;
if (ret)
return ret;
@@ -13134,6 +13150,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.setup_mce = vmx_setup_mce,
+ .get_vmcs12_pages = nested_get_vmcs12_pages,
+
.smi_allowed = vmx_smi_allowed,
.pre_enter_smm = vmx_pre_enter_smm,
.pre_leave_smm = vmx_pre_leave_smm,