From: Jan Kiszka Date: Wed, 14 Apr 2010 13:51:09 +0000 (+0200) Subject: KVM: x86: Push potential exception error code on task switches X-Git-Tag: v2.6.35-rc1~436^2~100 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=e269fb2189fb86d79d64c0ca74c6c1a549ad4aa3 KVM: x86: Push potential exception error code on task switches When a fault triggers a task switch, the error code, if existent, has to be pushed on the new task's stack. Implement the missing bits. Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index a1319c8..0b2729b 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -230,6 +230,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops); int emulator_task_switch(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, - u16 tss_selector, int reason); + u16 tss_selector, int reason, + bool has_error_code, u32 error_code); #endif /* _ASM_X86_KVM_X86_EMULATE_H */ diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 5d5e0a9..3602728 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -595,7 +595,8 @@ int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, void kvm_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg); int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, int seg); -int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason); +int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason, + bool has_error_code, u32 error_code); void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0); void kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3); diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 1d91d05..0e83105 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -244,6 +244,7 @@ struct __attribute__ ((__packed__)) vmcb { #define SVM_EXITINFOSHIFT_TS_REASON_IRET 36 #define SVM_EXITINFOSHIFT_TS_REASON_JMP 38 +#define SVM_EXITINFOSHIFT_TS_HAS_ERROR_CODE 44 #define SVM_EXIT_READ_CR0 0x000 #define SVM_EXIT_READ_CR3 0x003 diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index aace565..585d0ef 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2344,8 +2344,9 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, } static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, - struct x86_emulate_ops *ops, - u16 tss_selector, int reason) + struct x86_emulate_ops *ops, + u16 tss_selector, int reason, + bool has_error_code, u32 error_code) { struct desc_struct curr_tss_desc, next_tss_desc; int ret; @@ -2418,12 +2419,22 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, ops->set_cached_descriptor(&next_tss_desc, VCPU_SREG_TR, ctxt->vcpu); ops->set_segment_selector(tss_selector, VCPU_SREG_TR, ctxt->vcpu); + if (has_error_code) { + struct decode_cache *c = &ctxt->decode; + + c->op_bytes = c->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; + c->lock_prefix = 0; + c->src.val = (unsigned long) error_code; + emulate_push(ctxt); + } + return ret; } int emulator_task_switch(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, - u16 tss_selector, int reason) + u16 tss_selector, int reason, + bool has_error_code, u32 error_code) { struct decode_cache *c = &ctxt->decode; int rc; @@ -2431,12 +2442,15 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt, memset(c, 0, sizeof(struct decode_cache)); c->eip = ctxt->eip; memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); + c->dst.type = OP_NONE; - rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason); + rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason, + has_error_code, error_code); if (rc == X86EMUL_CONTINUE) { memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs); kvm_rip_write(ctxt->vcpu, c->eip); + rc = writeback(ctxt, ops); } return rc; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 87b36fb..78af522 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2222,6 +2222,8 @@ static int task_switch_interception(struct vcpu_svm *svm) svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_TYPE_MASK; uint32_t idt_v = svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_VALID; + bool has_error_code = false; + u32 error_code = 0; tss_selector = (u16)svm->vmcb->control.exit_info_1; @@ -2242,6 +2244,12 @@ static int task_switch_interception(struct vcpu_svm *svm) svm->vcpu.arch.nmi_injected = false; break; case SVM_EXITINTINFO_TYPE_EXEPT: + if (svm->vmcb->control.exit_info_2 & + (1ULL << SVM_EXITINFOSHIFT_TS_HAS_ERROR_CODE)) { + has_error_code = true; + error_code = + (u32)svm->vmcb->control.exit_info_2; + } kvm_clear_exception_queue(&svm->vcpu); break; case SVM_EXITINTINFO_TYPE_INTR: @@ -2258,7 +2266,8 @@ static int task_switch_interception(struct vcpu_svm *svm) (int_vec == OF_VECTOR || int_vec == BP_VECTOR))) skip_emulated_instruction(&svm->vcpu); - return kvm_task_switch(&svm->vcpu, tss_selector, reason); + return kvm_task_switch(&svm->vcpu, tss_selector, reason, + has_error_code, error_code); } static int cpuid_interception(struct vcpu_svm *svm) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index fb4a886..1b38d8a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3271,6 +3271,8 @@ static int handle_task_switch(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long exit_qualification; + bool has_error_code = false; + u32 error_code = 0; u16 tss_selector; int reason, type, idt_v; @@ -3293,6 +3295,13 @@ static int handle_task_switch(struct kvm_vcpu *vcpu) kvm_clear_interrupt_queue(vcpu); break; case INTR_TYPE_HARD_EXCEPTION: + if (vmx->idt_vectoring_info & + VECTORING_INFO_DELIVER_CODE_MASK) { + has_error_code = true; + error_code = + vmcs_read32(IDT_VECTORING_ERROR_CODE); + } + /* fall through */ case INTR_TYPE_SOFT_EXCEPTION: kvm_clear_exception_queue(vcpu); break; @@ -3307,7 +3316,8 @@ static int handle_task_switch(struct kvm_vcpu *vcpu) type != INTR_TYPE_NMI_INTR)) skip_emulated_instruction(vcpu); - if (!kvm_task_switch(vcpu, tss_selector, reason)) + if (!kvm_task_switch(vcpu, tss_selector, reason, has_error_code, + error_code)) return 0; /* clear all local breakpoint enable flags */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4099152..58a295c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4778,7 +4778,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, return 0; } -int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason) +int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason, + bool has_error_code, u32 error_code) { int cs_db, cs_l, ret; cache_all_regs(vcpu); @@ -4796,7 +4797,8 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason) ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; ret = emulator_task_switch(&vcpu->arch.emulate_ctxt, &emulate_ops, - tss_selector, reason); + tss_selector, reason, has_error_code, + error_code); if (ret == X86EMUL_CONTINUE) kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);