From 6dbb66c9e5d21ab5e40266b3a8e90d21677a1635 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Sun, 6 Feb 2011 17:03:09 +0000 Subject: [PATCH] hvm amd: Fix 32bit guest VM save/restore issues associated with SYSENTER MSRs This patch turn-on SYSENTER MSRs interception for 32bit guest VMs on AMD CPUs. With it, hvm_svm.guest_sysenter_xx fields always contain the canonical version of SYSENTER MSRs and are used in guest save/restore. The data fields in VMCB save area are updated as necessary. Reported-by: James Harper Signed-off-by: Wei Huang --- xen/arch/x86/hvm/svm/svm.c | 42 ++++++++++++++++++++++++-------------- 1 file changed, 27 insertions(+), 15 deletions(-) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index 4df855ff26..47c2a7bbae 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -224,10 +224,11 @@ static int svm_vmcb_restore(struct vcpu *v, struct hvm_hw_cpu *c) hvm_update_guest_cr(v, 2); hvm_update_guest_cr(v, 4); - v->arch.hvm_svm.guest_sysenter_cs = c->sysenter_cs; - v->arch.hvm_svm.guest_sysenter_esp = c->sysenter_esp; - v->arch.hvm_svm.guest_sysenter_eip = c->sysenter_eip; - + /* Load sysenter MSRs into both VMCB save area and VCPU fields. */ + vmcb->sysenter_cs = v->arch.hvm_svm.guest_sysenter_cs = c->sysenter_cs; + vmcb->sysenter_esp = v->arch.hvm_svm.guest_sysenter_esp = c->sysenter_esp; + vmcb->sysenter_eip = v->arch.hvm_svm.guest_sysenter_eip = c->sysenter_eip; + if ( paging_mode_hap(v->domain) ) { vmcb_set_np_enable(vmcb, 1); @@ -433,14 +434,6 @@ static void svm_update_guest_efer(struct vcpu *v) if ( lma ) new_efer |= EFER_LME; vmcb_set_efer(vmcb, new_efer); - - /* - * In legacy mode (EFER.LMA=0) we natively support SYSENTER/SYSEXIT with - * no need for MSR intercepts. When EFER.LMA=1 we must trap and emulate. - */ - svm_intercept_msr(v, MSR_IA32_SYSENTER_CS, lma); - svm_intercept_msr(v, MSR_IA32_SYSENTER_ESP, lma); - svm_intercept_msr(v, MSR_IA32_SYSENTER_EIP, lma); } static void svm_sync_vmcb(struct vcpu *v) @@ -1142,6 +1135,21 @@ static int svm_msr_write_intercept(unsigned int msr, uint64_t msr_content) { struct vcpu *v = current; struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb; + int sync = 0; + + switch ( msr ) + { + case MSR_IA32_SYSENTER_CS: + case MSR_IA32_SYSENTER_ESP: + case MSR_IA32_SYSENTER_EIP: + sync = 1; + break; + default: + break; + } + + if ( sync ) + svm_sync_vmcb(v); switch ( msr ) { @@ -1149,13 +1157,13 @@ static int svm_msr_write_intercept(unsigned int msr, uint64_t msr_content) goto gpf; case MSR_IA32_SYSENTER_CS: - v->arch.hvm_svm.guest_sysenter_cs = msr_content; + vmcb->sysenter_cs = v->arch.hvm_svm.guest_sysenter_cs = msr_content; break; case MSR_IA32_SYSENTER_ESP: - v->arch.hvm_svm.guest_sysenter_esp = msr_content; + vmcb->sysenter_esp = v->arch.hvm_svm.guest_sysenter_esp = msr_content; break; case MSR_IA32_SYSENTER_EIP: - v->arch.hvm_svm.guest_sysenter_eip = msr_content; + vmcb->sysenter_eip = v->arch.hvm_svm.guest_sysenter_eip = msr_content; break; case MSR_IA32_DEBUGCTLMSR: @@ -1213,6 +1221,10 @@ static int svm_msr_write_intercept(unsigned int msr, uint64_t msr_content) wrmsr_hypervisor_regs(msr, msr_content); break; } + + if ( sync ) + svm_vmload(vmcb); + return X86EMUL_OKAY; gpf: -- 2.30.2