From b3dbf89e676e47ef3b10802f9aba5a8e04aba132 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 16 Jun 2009 12:36:33 +0300 Subject: [PATCH] KVM: SVM: Don't save/restore host cr2 The host never reads cr2 in process context, so are free to clobber it. The vmx code does this, so we can safely remove the save/restore code. Signed-off-by: Avi Kivity --- arch/x86/kvm/svm.c | 17 ----------------- 1 file changed, 17 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 060aa9f5571..132be0c7c3e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -81,7 +81,6 @@ struct vcpu_svm { u64 host_user_msrs[NR_HOST_SAVE_USER_MSRS]; u64 host_gs_base; - unsigned long host_cr2; u32 *msrpm; struct vmcb *hsave; @@ -186,19 +185,6 @@ static inline void invlpga(unsigned long addr, u32 asid) asm volatile (__ex(SVM_INVLPGA) :: "a"(addr), "c"(asid)); } -static inline unsigned long kvm_read_cr2(void) -{ - unsigned long cr2; - - asm volatile ("mov %%cr2, %0" : "=r" (cr2)); - return cr2; -} - -static inline void kvm_write_cr2(unsigned long val) -{ - asm volatile ("mov %0, %%cr2" :: "r" (val)); -} - static inline void force_new_asid(struct kvm_vcpu *vcpu) { to_svm(vcpu)->asid_generation--; @@ -2527,7 +2513,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) fs_selector = kvm_read_fs(); gs_selector = kvm_read_gs(); ldt_selector = kvm_read_ldt(); - svm->host_cr2 = kvm_read_cr2(); if (!is_nested(svm)) svm->vmcb->save.cr2 = vcpu->arch.cr2; /* required for live migration with NPT */ @@ -2614,8 +2599,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp; vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip; - kvm_write_cr2(svm->host_cr2); - kvm_load_fs(fs_selector); kvm_load_gs(gs_selector); kvm_load_ldt(ldt_selector); -- 2.11.4.GIT