On 07/19/2010 06:30 PM, Gleb Natapov wrote:
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page.
-static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
- u32 error_code)
+static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
+ bool sync)
'sync' means something else in the shadow mmu. Please rename to
something longer, maybe 'apf_completion'.
Alternatively, split to two functions, a base function that doesn't do
apf and a wrapper that handles apf.
@@ -505,6 +506,37 @@ out_unlock:
return 0;
}
+static int FNAME(page_fault_other_cr3)(struct kvm_vcpu *vcpu, gpa_t cr3,
+ gva_t addr, u32 error_code)
+{
+ int r = 0;
+ gpa_t curr_cr3 = vcpu->arch.cr3;
+
+ if (curr_cr3 != cr3) {
+ /*
+ * We do page fault on behalf of a process that is sleeping
+ * because of async PF. PV guest takes reference to mm that cr3
+ * belongs too, so it has to be valid here.
+ */
+ kvm_set_cr3(vcpu, cr3);
+ if (kvm_mmu_reload(vcpu))
+ goto switch_cr3;
+ }
With nested virtualization, we need to switch cr0, cr4, and efer as well...
+
+ r = FNAME(page_fault)(vcpu, addr, error_code, true);
+
+ if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu))
+ kvm_mmu_sync_roots(vcpu);
Why is this needed?
+
+switch_cr3:
+ if (curr_cr3 != vcpu->arch.cr3) {
+ kvm_set_cr3(vcpu, curr_cr3);
+ kvm_mmu_reload(vcpu);
+ }
+
+ return r;
+}
This has the nasty effect of flushing the TLB on AMD.
+
static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
{
struct kvm_shadow_walk_iterator iterator;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2603cc4..5482db0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5743,6 +5743,15 @@ void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
}
EXPORT_SYMBOL_GPL(kvm_set_rflags);
+void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu,
+ struct kvm_async_pf *work)
+{
+ if (!vcpu->arch.mmu.page_fault_other_cr3 || is_error_page(work->page))
+ return;
+ vcpu->arch.mmu.page_fault_other_cr3(vcpu, work->arch.cr3, work->gva,
+ work->arch.error_code);
+}
+
static int apf_put_user(struct kvm_vcpu *vcpu, u32 val)
{
if (unlikely(vcpu->arch.apf_memslot_ver !=
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f56e8ac..de1d5b6 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1348,6 +1348,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
spin_lock(&vcpu->async_pf_lock);
list_del(&work->link);
spin_unlock(&vcpu->async_pf_lock);
+ kvm_arch_async_page_ready(vcpu, work);
put_page(work->page);
async_pf_work_free(work);
list_del(&work->queue);
@@ -1366,6 +1367,7 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
list_del(&work->queue);
vcpu->async_pf_queued--;
+ kvm_arch_async_page_ready(vcpu, work);
kvm_arch_inject_async_page_present(vcpu, work);
put_page(work->page);
--
error compiling committee.c: too many arguments to function
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