diff mbox

[07/11] Retry fault before vmentry

Message ID 1257076590-29559-8-git-send-email-gleb@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gleb Natapov Nov. 1, 2009, 11:56 a.m. UTC
None
diff mbox

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e3cdbfe..6c781ea 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -241,6 +241,8 @@  struct kvm_mmu_async_pf {
 	struct list_head link;
 	struct kvm_vcpu *vcpu;
 	struct mm_struct *mm;
+	gpa_t cr3;
+	u32 error_code;
 	gva_t gva;
 	unsigned long addr;
 	u64 token;
@@ -267,7 +269,7 @@  struct kvm_pio_request {
  */
 struct kvm_mmu {
 	void (*new_cr3)(struct kvm_vcpu *vcpu);
-	int (*page_fault)(struct kvm_vcpu *vcpu, gva_t gva, u32 err);
+	int (*page_fault)(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gva, u32 err);
 	void (*free)(struct kvm_vcpu *vcpu);
 	gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva);
 	void (*prefetch_page)(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 31e837b..abe1ce9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2171,7 +2171,7 @@  static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
 	return vaddr;
 }
 
-static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
+static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gva,
 				u32 error_code)
 {
 	gfn_t gfn;
@@ -2322,6 +2322,8 @@  void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
 			spin_lock(&vcpu->arch.mmu_async_pf_lock);
 			list_del(&work->link);
 			spin_unlock(&vcpu->arch.mmu_async_pf_lock);
+			vcpu->arch.mmu.page_fault(vcpu, (gpa_t)-1, work->gva,
+						  work->error_code);
 			put_page(work->page);
 			async_pf_work_free(work);
 		}
@@ -2338,6 +2340,7 @@  void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
 	list_del(&work->link);
 	spin_unlock(&vcpu->arch.mmu_async_pf_lock);
 
+	vcpu->arch.mmu.page_fault(vcpu, (gpa_t)-1, work->gva, work->error_code);
 	vcpu->arch.pv_shm->reason = KVM_PV_REASON_PAGE_READY;
 	vcpu->arch.pv_shm->param = work->token;
 	kvm_inject_page_fault(vcpu, work->gva, 0);
@@ -2363,7 +2366,8 @@  static bool can_do_async_pf(struct kvm_vcpu *vcpu)
 	return !!(kvm_seg.selector & 3);
 }
 
-static int setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
+static int setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gva,
+			  gfn_t gfn, u32 error_code)
 {
 	struct kvm_mmu_async_pf *work;
 
@@ -2378,6 +2382,8 @@  static int setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
 	atomic_set(&work->used, 1);
 	work->page = NULL;
 	work->vcpu = vcpu;
+	work->cr3 = cr3;
+	work->error_code = error_code;
 	work->gva = gva;
 	work->addr = gfn_to_hva(vcpu->kvm, gfn);
 	work->token = (vcpu->arch.async_pf_id++ << 12) | vcpu->vcpu_id;
@@ -2403,7 +2409,7 @@  retry_sync:
 	return 0;
 }
 
-static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
+static int tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t gpa,
 				u32 error_code)
 {
 	pfn_t pfn;
@@ -2426,7 +2432,7 @@  static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
 	smp_rmb();
 
-	if (can_do_async_pf(vcpu)) {
+	if (cr3 != (gpa_t)-1 && can_do_async_pf(vcpu)) {
 		r = gfn_to_pfn_async(vcpu->kvm, gfn, &pfn);
 		trace_kvm_mmu_try_async_get_page(r, pfn);
 	} else {
@@ -2436,7 +2442,7 @@  do_sync:
 	}
 
 	if (!r) {
-		if (!setup_async_pf(vcpu, gpa, gfn))
+		if (!setup_async_pf(vcpu, cr3, gpa, gfn, error_code))
 			goto do_sync;
 		return 0;
 	}
@@ -3006,7 +3012,7 @@  int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
 	int r;
 	enum emulation_result er;
 
-	r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
+	r = vcpu->arch.mmu.page_fault(vcpu, vcpu->arch.cr3, cr2, error_code);
 	if (r < 0)
 		goto out;
 
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 9fe2ecd..b1fe61f 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -375,7 +375,7 @@  static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
  *  Returns: 1 if we need to emulate the instruction, 0 otherwise, or
  *           a negative value on error.
  */
-static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
+static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t cr3, gva_t addr,
 			       u32 error_code)
 {
 	int write_fault = error_code & PFERR_WRITE_MASK;
@@ -388,6 +388,7 @@  static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	pfn_t pfn;
 	int level = PT_PAGE_TABLE_LEVEL;
 	unsigned long mmu_seq;
+	gpa_t curr_cr3 = vcpu->arch.cr3;
 
 	pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
 	kvm_mmu_audit(vcpu, "pre page fault");
@@ -396,6 +397,13 @@  static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	if (r)
 		return r;
 
+	if (curr_cr3 != cr3) {
+		vcpu->arch.cr3 = cr3;
+		paging_new_cr3(vcpu);
+		if (kvm_mmu_reload(vcpu))
+			goto switch_cr3;
+	}
+
 	/*
 	 * Look up the guest pte for the faulting address.
 	 */
@@ -406,6 +414,8 @@  static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	 * The page is not mapped by the guest.  Let the guest handle it.
 	 */
 	if (!r) {
+		if (curr_cr3 != vcpu->arch.cr3)
+			goto switch_cr3;
 		pgprintk("%s: guest page fault\n", __func__);
 		inject_page_fault(vcpu, addr, walker.error_code);
 		vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
@@ -420,7 +430,7 @@  static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	mmu_seq = vcpu->kvm->mmu_notifier_seq;
 	smp_rmb();
 
-	if (can_do_async_pf(vcpu)) {
+	if (cr3 != (gpa_t)-1 && can_do_async_pf(vcpu)) {
 		r = gfn_to_pfn_async(vcpu->kvm, walker.gfn, &pfn);
 		trace_kvm_mmu_try_async_get_page(r, pfn);
 	} else {
@@ -430,13 +440,17 @@  do_sync:
 	}
 
 	if (!r) {
-		if (!setup_async_pf(vcpu, addr, walker.gfn))
+		if (!setup_async_pf(vcpu, cr3, addr, walker.gfn, error_code))
 			goto do_sync;
+		if (curr_cr3 != vcpu->arch.cr3)
+			goto switch_cr3;
 		return 0;
 	}
 
 	/* mmio */
 	if (is_error_pfn(pfn)) {
+		if (curr_cr3 != vcpu->arch.cr3)
+			goto switch_cr3;
 		pgprintk("gfn %lx is mmio\n", walker.gfn);
 		kvm_release_pfn_clean(pfn);
 		return 1;
@@ -458,12 +472,22 @@  do_sync:
 	kvm_mmu_audit(vcpu, "post page fault (fixed)");
 	spin_unlock(&vcpu->kvm->mmu_lock);
 
+	if (curr_cr3 != vcpu->arch.cr3)
+		goto switch_cr3;
+
 	return write_pt;
 
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
 	kvm_release_pfn_clean(pfn);
-	return 0;
+switch_cr3:
+	if (curr_cr3 != vcpu->arch.cr3) {
+		vcpu->arch.cr3 = curr_cr3;
+		paging_new_cr3(vcpu);
+		kvm_mmu_reload(vcpu);
+	}
+
+	return write_pt;
 }
 
 static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)