diff options
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 9e449167e71b..47f9c7156609 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -42,8 +42,6 @@ #include <asm/reboot.h> #include <asm/fpu/api.h> -#include <asm/virtext.h> - #include <trace/events/ipi.h> #include "trace.h" @@ -582,9 +580,32 @@ out: preempt_enable(); } +static inline void kvm_cpu_svm_disable(void) +{ + uint64_t efer; + + wrmsrl(MSR_VM_HSAVE_PA, 0); + rdmsrl(MSR_EFER, efer); + if (efer & EFER_SVME) { + /* + * Force GIF=1 prior to disabling SVM to ensure INIT and NMI + * aren't blocked, e.g. if a fatal error occurred between CLGI + * and STGI. Note, STGI may #UD if SVM is disabled from NMI + * context between reading EFER and executing STGI. In that + * case, GIF must already be set, otherwise the NMI would have + * been blocked, so just eat the fault. + */ + asm_volatile_goto("1: stgi\n\t" + _ASM_EXTABLE(1b, %l[fault]) + ::: "memory" : fault); +fault: + wrmsrl(MSR_EFER, efer & ~EFER_SVME); + } +} + static void svm_emergency_disable(void) { - cpu_svm_disable(); + kvm_cpu_svm_disable(); } static void svm_hardware_disable(void) @@ -593,7 +614,7 @@ static void svm_hardware_disable(void) if (tsc_scaling) __svm_write_tsc_multiplier(SVM_TSC_RATIO_DEFAULT); - cpu_svm_disable(); + kvm_cpu_svm_disable(); amd_pmu_disable_virt(); } |