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authorAvi Kivity <avi@qumranet.com>2007-01-06 03:36:54 +0300
committerLinus Torvalds <torvalds@woody.osdl.org>2007-01-06 10:55:27 +0300
commite2dec939db126989808853d218e426daaeebc9e2 (patch)
tree5c742e609e43090df396fc1c7a6b4c526099dbea
parent714b93da1a6d97307dfafb9915517879d8a66c0d (diff)
downloadlinux-sunxi-e2dec939db126989808853d218e426daaeebc9e2.tar.xz
[PATCH] KVM: MMU: Detect oom conditions and propagate error to userspace
Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/kvm/mmu.c32
-rw-r--r--drivers/kvm/paging_tmpl.h8
-rw-r--r--drivers/kvm/svm.c14
-rw-r--r--drivers/kvm/vmx.c15
4 files changed, 50 insertions, 19 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index e96362aa7947..7761089ef3bc 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -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;
}
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 4e6670ff1847..32b385188454 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -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.
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 99250011a471..af1e7b3f9171 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -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 @@ again:
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 @@ again:
goto again;
}
post_kvm_run_save(vcpu, kvm_run);
- return 0;
+ return r;
}
static void svm_flush_tlb(struct kvm_vcpu *vcpu)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 59178ad4d344..ed3956739771 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -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 @@ again:
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 @@ again:
}
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 @@ again:
}
post_kvm_run_save(vcpu, kvm_run);
- return 0;
+ return r;
}
static void vmx_flush_tlb(struct kvm_vcpu *vcpu)