Commit e2dec939 authored by Avi Kivity's avatar Avi Kivity Committed by Linus Torvalds
Browse files

[PATCH] KVM: MMU: Detect oom conditions and propagate error to userspace 



Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 714b93da

drivers/kvm/mmu.c

+21 −11
Original line number Diff line number Diff line
@@ -166,19 +166,20 @@ static int is_rmap_pte(u64 pte) 
		== (PT_WRITABLE_MASK | PT_PRESENT_MASK);

}



static void mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,

static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,

				  size_t objsize, int min)

{

	void *obj;



	if (cache->nobjs >= min)

		return;

		return 0;

	while (cache->nobjs < ARRAY_SIZE(cache->objects)) {

		obj = kzalloc(objsize, GFP_NOWAIT);

		if (!obj)

			BUG();

			return -ENOMEM;

		cache->objects[cache->nobjs++] = obj;

	}

	return 0;

}



static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
@@ -187,12 +188,18 @@ static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) 
		kfree(mc->objects[--mc->nobjs]);

}



static void mmu_topup_memory_caches(struct kvm_vcpu *vcpu)

static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)

{

	mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,

	int r;



	r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,

				   sizeof(struct kvm_pte_chain), 4);

	mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,

	if (r)

		goto out;

	r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,

				   sizeof(struct kvm_rmap_desc), 1);

out:

	return r;

}



static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
@@ -824,8 +831,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, 
{

	gpa_t addr = gva;

	hpa_t paddr;

	int r;



	mmu_topup_memory_caches(vcpu);

	r = mmu_topup_memory_caches(vcpu);

	if (r)

		return r;



	ASSERT(vcpu);

	ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
@@ -1052,7 +1062,7 @@ int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) 
	r = init_kvm_mmu(vcpu);

	if (r < 0)

		goto out;

	mmu_topup_memory_caches(vcpu);

	r = mmu_topup_memory_caches(vcpu);

out:

	return r;

}

drivers/kvm/paging_tmpl.h

+6 −2
Original line number Diff line number Diff line
@@ -339,7 +339,8 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu, 
 *   - normal guest page fault due to the guest pte marked not present, not

 *     writable, or not executable

 *

 *  Returns: 1 if we need to emulate the instruction, 0 otherwise

 *  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,

			       u32 error_code)
@@ -351,10 +352,13 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, 
	u64 *shadow_pte;

	int fixed;

	int write_pt = 0;

	int r;



	pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code);



	mmu_topup_memory_caches(vcpu);

	r = mmu_topup_memory_caches(vcpu);

	if (r)

		return r;



	/*

	 * Look up the shadow pte for the faulting address.

drivers/kvm/svm.c

+11 −3
Original line number Diff line number Diff line
@@ -852,6 +852,7 @@ static int pf_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	u64 fault_address;

	u32 error_code;

	enum emulation_result er;

	int r;



	if (is_external_interrupt(exit_int_info))

		push_irq(vcpu, exit_int_info & SVM_EVTINJ_VEC_MASK);
@@ -860,7 +861,12 @@ static int pf_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 


	fault_address  = vcpu->svm->vmcb->control.exit_info_2;

	error_code = vcpu->svm->vmcb->control.exit_info_1;

	if (!kvm_mmu_page_fault(vcpu, fault_address, error_code)) {

	r = kvm_mmu_page_fault(vcpu, fault_address, error_code);

	if (r < 0) {

		spin_unlock(&vcpu->kvm->lock);

		return r;

	}

	if (!r) {

		spin_unlock(&vcpu->kvm->lock);

		return 1;

	}
@@ -1398,6 +1404,7 @@ static int svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	u16 fs_selector;

	u16 gs_selector;

	u16 ldt_selector;

	int r;



again:

	do_interrupt_requests(vcpu, kvm_run);
@@ -1565,7 +1572,8 @@ static int svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		return 0;

	}



	if (handle_exit(vcpu, kvm_run)) {

	r = handle_exit(vcpu, kvm_run);

	if (r > 0) {

		if (signal_pending(current)) {

			++kvm_stat.signal_exits;

			post_kvm_run_save(vcpu, kvm_run);
@@ -1581,7 +1589,7 @@ static int svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		goto again;

	}

	post_kvm_run_save(vcpu, kvm_run);

	return 0;

	return r;

}



static void svm_flush_tlb(struct kvm_vcpu *vcpu)

drivers/kvm/vmx.c

+12 −3
Original line number Diff line number Diff line
@@ -1289,6 +1289,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	unsigned long cr2, rip;

	u32 vect_info;

	enum emulation_result er;

	int r;



	vect_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);

	intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
@@ -1317,7 +1318,12 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		cr2 = vmcs_readl(EXIT_QUALIFICATION);



		spin_lock(&vcpu->kvm->lock);

		if (!kvm_mmu_page_fault(vcpu, cr2, error_code)) {

		r = kvm_mmu_page_fault(vcpu, cr2, error_code);

		if (r < 0) {

			spin_unlock(&vcpu->kvm->lock);

			return r;

		}

		if (!r) {

			spin_unlock(&vcpu->kvm->lock);

			return 1;

		}
@@ -1680,6 +1686,7 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	u8 fail;

	u16 fs_sel, gs_sel, ldt_sel;

	int fs_gs_ldt_reload_needed;

	int r;



again:

	/*
@@ -1853,6 +1860,7 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (fail) {

		kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY;

		kvm_run->exit_reason = vmcs_read32(VM_INSTRUCTION_ERROR);

		r = 0;

	} else {

		if (fs_gs_ldt_reload_needed) {

			load_ldt(ldt_sel);
@@ -1872,7 +1880,8 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		}

		vcpu->launched = 1;

		kvm_run->exit_type = KVM_EXIT_TYPE_VM_EXIT;

		if (kvm_handle_exit(kvm_run, vcpu)) {

		r = kvm_handle_exit(kvm_run, vcpu);

		if (r > 0) {

			/* Give scheduler a change to reschedule. */

			if (signal_pending(current)) {

				++kvm_stat.signal_exits;
@@ -1892,7 +1901,7 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	}



	post_kvm_run_save(vcpu, kvm_run);

	return 0;

	return r;

}



static void vmx_flush_tlb(struct kvm_vcpu *vcpu)