From: Glauber Costa Date: Tue, 6 Oct 2009 17:24:50 +0000 (-0400) Subject: KVM: x86: include pvclock MSRs in msrs_to_save X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e3267cbbbfbcbe9c18833e89b10beabb1117cb55;p=linux-beck.git KVM: x86: include pvclock MSRs in msrs_to_save For a while now, we are issuing a rdmsr instruction to find out which msrs in our save list are really supported by the underlying machine. However, it fails to account for kvm-specific msrs, such as the pvclock ones. This patch moves then to the beginning of the list, and skip testing them. Cc: stable@kernel.org Signed-off-by: Glauber Costa Signed-off-by: Marcelo Tosatti --- diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 385cd0a1e23d..4de5bc0a8e86 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -503,16 +503,19 @@ static inline u32 bit(int bitno) * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. * * This list is modified at module load time to reflect the - * capabilities of the host cpu. + * capabilities of the host cpu. This capabilities test skips MSRs that are + * kvm-specific. Those are put in the beginning of the list. */ + +#define KVM_SAVE_MSRS_BEGIN 2 static u32 msrs_to_save[] = { + MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK, MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, MSR_K6_STAR, #ifdef CONFIG_X86_64 MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR, #endif - MSR_IA32_TSC, MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK, - MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA + MSR_IA32_TSC, MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA }; static unsigned num_msrs_to_save; @@ -2446,7 +2449,8 @@ static void kvm_init_msr_list(void) u32 dummy[2]; unsigned i, j; - for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) { + /* skip the first msrs in the list. KVM-specific */ + 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; if (j < i)