From 989e3992d2eca32c3f1404f2bc91acda3aa122d8 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 20 Jun 2018 22:01:22 -0400 Subject: [PATCH] x86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs The IA32_FLUSH_CMD MSR needs only to be written on VMENTER. Extend add_atomic_switch_msr() with an entry_only parameter to allow storing the MSR only in the guest (ENTRY) MSR array. Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Thomas Gleixner --- arch/x86/kvm/vmx.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index bde1602..fd80f93 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2484,9 +2484,9 @@ static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx, } static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr, - u64 guest_val, u64 host_val) + u64 guest_val, u64 host_val, bool entry_only) { - int i, j; + int i, j = 0; struct msr_autoload *m = &vmx->msr_autoload; switch (msr) { @@ -2522,7 +2522,9 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr, } i = find_msr(&m->guest, msr); - j = find_msr(&m->host, msr); + if (!entry_only) + j = find_msr(&m->host, msr); + if (i == NR_AUTOLOAD_MSRS || j == NR_AUTOLOAD_MSRS) { printk_once(KERN_WARNING "Not enough msr switch entries. " "Can't add msr %x\n", msr); @@ -2532,12 +2534,16 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr, i = m->guest.nr++; vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr); } + m->guest.val[i].index = msr; + m->guest.val[i].value = guest_val; + + if (entry_only) + return; + if (j < 0) { j = m->host.nr++; vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr); } - m->guest.val[i].index = msr; - m->guest.val[i].value = guest_val; m->host.val[j].index = msr; m->host.val[j].value = host_val; } @@ -2583,7 +2589,7 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset) guest_efer &= ~EFER_LME; if (guest_efer != host_efer) add_atomic_switch_msr(vmx, MSR_EFER, - guest_efer, host_efer); + guest_efer, host_efer, false); return false; } else { guest_efer &= ~ignore_bits; @@ -4037,7 +4043,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vcpu->arch.ia32_xss = data; if (vcpu->arch.ia32_xss != host_xss) add_atomic_switch_msr(vmx, MSR_IA32_XSS, - vcpu->arch.ia32_xss, host_xss); + vcpu->arch.ia32_xss, host_xss, false); else clear_atomic_switch_msr(vmx, MSR_IA32_XSS); break; @@ -10040,7 +10046,7 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx) clear_atomic_switch_msr(vmx, msrs[i].msr); else add_atomic_switch_msr(vmx, msrs[i].msr, msrs[i].guest, - msrs[i].host); + msrs[i].host, false); } static void vmx_arm_hv_timer(struct kvm_vcpu *vcpu) -- 2.7.4