| Message ID | DE8DF0795D48FD4CA783C40EC82923350155757D@SHSMSX152.ccr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Il 10/03/2014 09:48, Liu, Jinsong ha scritto: > From 5854070994c5002b3a37577165ed3e82f36f712d Mon Sep 17 00:00:00 2001 > From: Liu Jinsong <jinsong.liu@intel.com> > Date: Sat, 8 Mar 2014 04:40:02 +0800 > Subject: [PATCH] KVM: x86: Work around buggy MPX platform > > Work around buggy MPX platform which support MSR_IA32_BNDCFGS > but has issue at, say, VMX ucode. > > Signed-off-by: Liu Jinsong <jinsong.liu@intel.com> > --- > arch/x86/kvm/x86.c | 14 +++++++++++++- > 1 files changed, 13 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 1e91a24..1fc184d 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3936,6 +3936,16 @@ static void kvm_init_msr_list(void) > for (i = j = KVM_SAVE_MSRS_BEGIN; i < ARRAY_SIZE(msrs_to_save); i++) { > if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) > continue; > + > + /* > + * Work around some buggy MPX platform which support > + * MSR_IA32_BNDCFGS but has issue at, say, VMX ucode. > + */ > + if ((msrs_to_save[i] == MSR_IA32_BNDCFGS) && Too many parentheses in this "if". > + (kvm_x86_ops->mpx_supported ? > + !kvm_x86_ops->mpx_supported() : 1)) Better: "!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported()" but I'm leaning towards adding an implementation of mpx_supported to SVM too (it will always return false). > + continue; > + > if (j < i) > msrs_to_save[j] = msrs_to_save[i]; > j++; > @@ -5576,9 +5586,11 @@ int kvm_arch_init(void *opaque) > goto out_free_percpu; > > kvm_set_mmio_spte_mask(); > - kvm_init_msr_list(); > > kvm_x86_ops = ops; > + > + kvm_init_msr_list(); > + > kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK, > PT_DIRTY_MASK, PT64_NX_MASK, 0); > > Thanks Liu. Indeed I could not reproduce Robert's issue, though it might be possible to get it with nested virtualization. I'll send a similar patch that I was testing. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1e91a24..1fc184d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3936,6 +3936,16 @@ static void kvm_init_msr_list(void) for (i = j = KVM_SAVE_MSRS_BEGIN; i < ARRAY_SIZE(msrs_to_save); i++) { if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) continue; + + /* + * Work around some buggy MPX platform which support + * MSR_IA32_BNDCFGS but has issue at, say, VMX ucode. + */ + if ((msrs_to_save[i] == MSR_IA32_BNDCFGS) && + (kvm_x86_ops->mpx_supported ? + !kvm_x86_ops->mpx_supported() : 1)) + continue; + if (j < i) msrs_to_save[j] = msrs_to_save[i]; j++; @@ -5576,9 +5586,11 @@ int kvm_arch_init(void *opaque) goto out_free_percpu; kvm_set_mmio_spte_mask(); - kvm_init_msr_list(); kvm_x86_ops = ops; + + kvm_init_msr_list(); + kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK, PT_DIRTY_MASK, PT64_NX_MASK, 0);