From patchwork Thu Sep 27 14:27:22 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Quantal, 1/1] Revert "KVM: VMX: Fix KVM_SET_SREGS with big real mode segments" From: Joseph Salisbury X-Patchwork-Id: 187382 Message-Id: To: kernel-team@lists.ubuntu.com Date: Thu, 27 Sep 2012 10:27:22 -0400 From: Joseph Salisbury BugLink: http://bugs.launchpad.net/bugs/1045027 This reverts commit b398aa3174cdfd4d85964fa84004e53ce6a13cab. --- arch/x86/kvm/vmx.c | 70 +++++++++------------------------------------------- 1 file changed, 12 insertions(+), 58 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index b2a349d..576a235 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -618,10 +618,6 @@ static void kvm_cpu_vmxon(u64 addr); static void kvm_cpu_vmxoff(void); static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3); static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr); -static void vmx_set_segment(struct kvm_vcpu *vcpu, - struct kvm_segment *var, int seg); -static void vmx_get_segment(struct kvm_vcpu *vcpu, - struct kvm_segment *var, int seg); static DEFINE_PER_CPU(struct vmcs *, vmxarea); static DEFINE_PER_CPU(struct vmcs *, current_vmcs); @@ -2791,7 +2787,6 @@ static void enter_rmode(struct kvm_vcpu *vcpu) { unsigned long flags; struct vcpu_vmx *vmx = to_vmx(vcpu); - struct kvm_segment var; if (enable_unrestricted_guest) return; @@ -2835,23 +2830,20 @@ static void enter_rmode(struct kvm_vcpu *vcpu) if (emulate_invalid_guest_state) goto continue_rmode; - vmx_get_segment(vcpu, &var, VCPU_SREG_SS); - vmx_set_segment(vcpu, &var, VCPU_SREG_SS); - - vmx_get_segment(vcpu, &var, VCPU_SREG_CS); - vmx_set_segment(vcpu, &var, VCPU_SREG_CS); - - vmx_get_segment(vcpu, &var, VCPU_SREG_ES); - vmx_set_segment(vcpu, &var, VCPU_SREG_ES); + vmcs_write16(GUEST_SS_SELECTOR, vmcs_readl(GUEST_SS_BASE) >> 4); + vmcs_write32(GUEST_SS_LIMIT, 0xffff); + vmcs_write32(GUEST_SS_AR_BYTES, 0xf3); - vmx_get_segment(vcpu, &var, VCPU_SREG_DS); - vmx_set_segment(vcpu, &var, VCPU_SREG_DS); + vmcs_write32(GUEST_CS_AR_BYTES, 0xf3); + vmcs_write32(GUEST_CS_LIMIT, 0xffff); + if (vmcs_readl(GUEST_CS_BASE) == 0xffff0000) + vmcs_writel(GUEST_CS_BASE, 0xf0000); + vmcs_write16(GUEST_CS_SELECTOR, vmcs_readl(GUEST_CS_BASE) >> 4); - vmx_get_segment(vcpu, &var, VCPU_SREG_GS); - vmx_set_segment(vcpu, &var, VCPU_SREG_GS); - - vmx_get_segment(vcpu, &var, VCPU_SREG_FS); - vmx_set_segment(vcpu, &var, VCPU_SREG_FS); + fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.es); + fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.ds); + fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.gs); + fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.fs); continue_rmode: kvm_mmu_reset_context(vcpu); @@ -3256,44 +3248,6 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu, vmcs_write32(sf->ar_bytes, ar); __clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail); - - /* - * Fix segments for real mode guest in hosts that don't have - * "unrestricted_mode" or it was disabled. - * This is done to allow migration of the guests from hosts with - * unrestricted guest like Westmere to older host that don't have - * unrestricted guest like Nehelem. - */ - if (!enable_unrestricted_guest && vmx->rmode.vm86_active) { - switch (seg) { - case VCPU_SREG_CS: - vmcs_write32(GUEST_CS_AR_BYTES, 0xf3); - vmcs_write32(GUEST_CS_LIMIT, 0xffff); - if (vmcs_readl(GUEST_CS_BASE) == 0xffff0000) - vmcs_writel(GUEST_CS_BASE, 0xf0000); - vmcs_write16(GUEST_CS_SELECTOR, - vmcs_readl(GUEST_CS_BASE) >> 4); - break; - case VCPU_SREG_ES: - fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.es); - break; - case VCPU_SREG_DS: - fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.ds); - break; - case VCPU_SREG_GS: - fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.gs); - break; - case VCPU_SREG_FS: - fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.fs); - break; - case VCPU_SREG_SS: - vmcs_write16(GUEST_SS_SELECTOR, - vmcs_readl(GUEST_SS_BASE) >> 4); - vmcs_write32(GUEST_SS_LIMIT, 0xffff); - vmcs_write32(GUEST_SS_AR_BYTES, 0xf3); - break; - } - } } static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)