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

[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
......@@ -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,
size_t objsize, int min)
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,
sizeof(struct kvm_pte_chain), 4);
mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
sizeof(struct kvm_rmap_desc), 1);
int r;
r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
sizeof(struct kvm_pte_chain), 4);
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;
}
......
......@@ -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.
......
......@@ -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)
......
......@@ -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)
......
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