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authorTakashi Iwai <tiwai@suse.de>2021-04-26 16:59:21 +0200
committerTakashi Iwai <tiwai@suse.de>2021-04-26 16:59:21 +0200
commit0301201b7181a927b59421097a01ee98683aa67c (patch)
tree74b525a64009c7f2770438e01e87d0111c354b86 /arch/x86/kvm/svm/nested.c
parent1c98f574403dbcf2eb832d5535a10d967333ef2d (diff)
parentffc9841d5200a484ea0ecc645157b4d7b873f3a6 (diff)
Merge tag 'asoc-v5.13' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v5.13 A lot of changes here for quite a quiet release in subsystem terms - there's been a lot of fixes and cleanups all over the subsystem both from generic work and from people working on specific drivers. - More cleanup and consolidation work in the core and the generic card drivers from Morimoto-san. - Lots of cppcheck fixes for Pierre-Louis Brossart. - New drivers for Freescale i.MX DMA over rpmsg, Mediatek MT6358 accessory detection, and Realtek RT1019, RT1316, RT711 and RT715.
Diffstat (limited to 'arch/x86/kvm/svm/nested.c')
-rw-r--r--arch/x86/kvm/svm/nested.c28
1 files changed, 23 insertions, 5 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 35891d9a1099..fb204eaa8bb3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -246,11 +246,18 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
return true;
}
-static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
+static bool nested_vmcb_check_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
{
struct kvm_vcpu *vcpu = &svm->vcpu;
bool vmcb12_lma;
+ /*
+ * FIXME: these should be done after copying the fields,
+ * to avoid TOC/TOU races. For these save area checks
+ * the possible damage is limited since kvm_set_cr0 and
+ * kvm_set_cr4 handle failure; EFER_SVME is an exception
+ * so it is force-set later in nested_prepare_vmcb_save.
+ */
if ((vmcb12->save.efer & EFER_SVME) == 0)
return false;
@@ -271,7 +278,7 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
return false;
- return nested_vmcb_check_controls(&vmcb12->control);
+ return true;
}
static void load_nested_vmcb_control(struct vcpu_svm *svm,
@@ -396,7 +403,14 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
svm->vmcb->save.gdtr = vmcb12->save.gdtr;
svm->vmcb->save.idtr = vmcb12->save.idtr;
kvm_set_rflags(&svm->vcpu, vmcb12->save.rflags | X86_EFLAGS_FIXED);
- svm_set_efer(&svm->vcpu, vmcb12->save.efer);
+
+ /*
+ * Force-set EFER_SVME even though it is checked earlier on the
+ * VMCB12, because the guest can flip the bit between the check
+ * and now. Clearing EFER_SVME would call svm_free_nested.
+ */
+ svm_set_efer(&svm->vcpu, vmcb12->save.efer | EFER_SVME);
+
svm_set_cr0(&svm->vcpu, vmcb12->save.cr0);
svm_set_cr4(&svm->vcpu, vmcb12->save.cr4);
svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = vmcb12->save.cr2;
@@ -468,7 +482,6 @@ int enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb12_gpa,
svm->nested.vmcb12_gpa = vmcb12_gpa;
- load_nested_vmcb_control(svm, &vmcb12->control);
nested_prepare_vmcb_control(svm);
nested_prepare_vmcb_save(svm, vmcb12);
@@ -515,7 +528,10 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
if (WARN_ON_ONCE(!svm->nested.initialized))
return -EINVAL;
- if (!nested_vmcb_checks(svm, vmcb12)) {
+ load_nested_vmcb_control(svm, &vmcb12->control);
+
+ if (!nested_vmcb_check_save(svm, vmcb12) ||
+ !nested_vmcb_check_controls(&svm->nested.ctl)) {
vmcb12->control.exit_code = SVM_EXIT_ERR;
vmcb12->control.exit_code_hi = 0;
vmcb12->control.exit_info_1 = 0;
@@ -1209,6 +1225,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
*/
if (!(save->cr0 & X86_CR0_PG))
goto out_free;
+ if (!(save->efer & EFER_SVME))
+ goto out_free;
/*
* All checks done, we can enter guest mode. L1 control fields