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authorPaolo Bonzini <pbonzini@redhat.com>2016-07-12 11:36:41 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2017-12-14 11:26:39 +0300
commit66336cab3531d3325ebde36a04725dddd0c42cb5 (patch)
treecfe09da682c97a58b7389f341e4d295b03cdceb9 /arch/x86/kvm/cpuid.c
parentdd307d017b445a3af4379c7ff548cb3da5ecde31 (diff)
downloadlinux-66336cab3531d3325ebde36a04725dddd0c42cb5.tar.xz
KVM: x86: add support for emulating UMIP
The User-Mode Instruction Prevention feature present in recent Intel processor prevents a group of instructions (sgdt, sidt, sldt, smsw, and str) from being executed with CPL > 0. Otherwise, a general protection fault is issued. UMIP instructions in general are also able to trigger vmexits, so we can actually emulate UMIP on older processors. This commit sets up the infrastructure so that kvm-intel.ko and kvm-amd.ko can set the UMIP feature bit for CPUID even if the feature is not actually available in hardware. Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
-rw-r--r--arch/x86/kvm/cpuid.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 77fb8732b47b..2b3b06458f6f 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -327,6 +327,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
+ unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
/* cpuid 1.edx */
const u32 kvm_cpuid_1_edx_x86_features =
@@ -473,6 +474,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
entry->ebx |= F(TSC_ADJUST);
entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
cpuid_mask(&entry->ecx, CPUID_7_ECX);
+ entry->ecx |= f_umip;
/* PKU is not yet implemented for shadow paging. */
if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
entry->ecx &= ~F(PKU);