From 8df25a328a6ca3bd0f048278f4d5ae0a1f6fadc1 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 10 Sep 2010 17:30:46 +0200 Subject: [PATCH] KVM: MMU: Track page fault data in struct vcpu This patch introduces a struct with two new fields in vcpu_arch for x86: * fault.address * fault.error_code This will be used to correctly propagate page faults back into the guest when we could have either an ordinary page fault or a nested page fault. In the case of a nested page fault the fault-address is different from the original address that should be walked. So we need to keep track about the real fault-address. Signed-off-by: Joerg Roedel Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_emulate.h | 1 - arch/x86/include/asm/kvm_host.h | 17 ++++++++++++----- arch/x86/kvm/emulate.c | 30 ++++++++++++++---------------- arch/x86/kvm/mmu.c | 6 ++---- arch/x86/kvm/paging_tmpl.h | 6 +++++- arch/x86/kvm/x86.c | 9 +++++---- 6 files changed, 38 insertions(+), 31 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 1bf1140..5187dd8 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -229,7 +229,6 @@ struct x86_emulate_ctxt { int exception; /* exception that happens during emulation or -1 */ u32 error_code; /* error code for exception */ bool error_code_valid; - unsigned long cr2; /* faulted address in case of #PF */ /* decode cache */ struct decode_cache decode; diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 009a4a1..3fde5b3 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -239,9 +239,7 @@ struct kvm_mmu { void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long root); unsigned long (*get_cr3)(struct kvm_vcpu *vcpu); int (*page_fault)(struct kvm_vcpu *vcpu, gva_t gva, u32 err); - void (*inject_page_fault)(struct kvm_vcpu *vcpu, - unsigned long addr, - u32 error_code); + void (*inject_page_fault)(struct kvm_vcpu *vcpu); void (*free)(struct kvm_vcpu *vcpu); gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva, u32 access, u32 *error); @@ -288,6 +286,16 @@ struct kvm_vcpu_arch { bool tpr_access_reporting; struct kvm_mmu mmu; + + /* + * This struct is filled with the necessary information to propagate a + * page fault into the guest + */ + struct { + u64 address; + unsigned error_code; + } fault; + /* only needed in kvm_pv_mmu_op() path, but it's hot so * put it here to avoid allocation */ struct kvm_pv_mmu_op_buffer mmu_op_buffer; @@ -624,8 +632,7 @@ void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr); void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code); void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr); void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code); -void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long cr2, - u32 error_code); +void kvm_inject_page_fault(struct kvm_vcpu *vcpu); bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl); int kvm_pic_set_irq(void *opaque, int irq, int level); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 27d2c22..2b08b78 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -487,11 +487,9 @@ static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err) emulate_exception(ctxt, GP_VECTOR, err, true); } -static void emulate_pf(struct x86_emulate_ctxt *ctxt, unsigned long addr, - int err) +static void emulate_pf(struct x86_emulate_ctxt *ctxt) { - ctxt->cr2 = addr; - emulate_exception(ctxt, PF_VECTOR, err, true); + emulate_exception(ctxt, PF_VECTOR, 0, true); } static void emulate_ud(struct x86_emulate_ctxt *ctxt) @@ -834,7 +832,7 @@ static int read_emulated(struct x86_emulate_ctxt *ctxt, rc = ops->read_emulated(addr, mc->data + mc->end, n, &err, ctxt->vcpu); if (rc == X86EMUL_PROPAGATE_FAULT) - emulate_pf(ctxt, addr, err); + emulate_pf(ctxt); if (rc != X86EMUL_CONTINUE) return rc; mc->end += n; @@ -921,7 +919,7 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, addr = dt.address + index * 8; ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) - emulate_pf(ctxt, addr, err); + emulate_pf(ctxt); return ret; } @@ -947,7 +945,7 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, addr = dt.address + index * 8; ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) - emulate_pf(ctxt, addr, err); + emulate_pf(ctxt); return ret; } @@ -1117,7 +1115,7 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt, &err, ctxt->vcpu); if (rc == X86EMUL_PROPAGATE_FAULT) - emulate_pf(ctxt, c->dst.addr.mem, err); + emulate_pf(ctxt); if (rc != X86EMUL_CONTINUE) return rc; break; @@ -1939,7 +1937,7 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, old_tss_base, err); + emulate_pf(ctxt); return ret; } @@ -1949,7 +1947,7 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, old_tss_base, err); + emulate_pf(ctxt); return ret; } @@ -1957,7 +1955,7 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, new_tss_base, err); + emulate_pf(ctxt); return ret; } @@ -1970,7 +1968,7 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, new_tss_base, err); + emulate_pf(ctxt); return ret; } } @@ -2081,7 +2079,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, old_tss_base, err); + emulate_pf(ctxt); return ret; } @@ -2091,7 +2089,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, old_tss_base, err); + emulate_pf(ctxt); return ret; } @@ -2099,7 +2097,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, new_tss_base, err); + emulate_pf(ctxt); return ret; } @@ -2112,7 +2110,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ - emulate_pf(ctxt, new_tss_base, err); + emulate_pf(ctxt); return ret; } } diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 86f7557c..9936727 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2566,11 +2566,9 @@ static unsigned long get_cr3(struct kvm_vcpu *vcpu) return vcpu->arch.cr3; } -static void inject_page_fault(struct kvm_vcpu *vcpu, - u64 addr, - u32 err_code) +static void inject_page_fault(struct kvm_vcpu *vcpu) { - vcpu->arch.mmu.inject_page_fault(vcpu, addr, err_code); + vcpu->arch.mmu.inject_page_fault(vcpu); } static void paging_free(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 68ee1b7..d07f48a 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -258,6 +258,10 @@ error: walker->error_code |= PFERR_FETCH_MASK; if (rsvd_fault) walker->error_code |= PFERR_RSVD_MASK; + + vcpu->arch.fault.address = addr; + vcpu->arch.fault.error_code = walker->error_code; + trace_kvm_mmu_walker_error(walker->error_code); return 0; } @@ -521,7 +525,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, */ if (!r) { pgprintk("%s: guest page fault\n", __func__); - inject_page_fault(vcpu, addr, walker.error_code); + inject_page_fault(vcpu); vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ return 0; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9d43477..48b74d2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -329,11 +329,12 @@ void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr) } EXPORT_SYMBOL_GPL(kvm_requeue_exception); -void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long addr, - u32 error_code) +void kvm_inject_page_fault(struct kvm_vcpu *vcpu) { + unsigned error_code = vcpu->arch.fault.error_code; + ++vcpu->stat.pf_guest; - vcpu->arch.cr2 = addr; + vcpu->arch.cr2 = vcpu->arch.fault.address; kvm_queue_exception_e(vcpu, PF_VECTOR, error_code); } @@ -4080,7 +4081,7 @@ static void inject_emulated_exception(struct kvm_vcpu *vcpu) { struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; if (ctxt->exception == PF_VECTOR) - kvm_inject_page_fault(vcpu, ctxt->cr2, ctxt->error_code); + kvm_inject_page_fault(vcpu); else if (ctxt->error_code_valid) kvm_queue_exception_e(vcpu, ctxt->exception, ctxt->error_code); else -- 2.7.4