[PATCH 16/22] KVM: MMU: Track page fault data in struct vcpu

Joerg Roedel
2010-04-27T10:39:08Z

This patch introduces two fields in vcpu_arch for x86:

* fault_address
* fault_error_code

This will be used to correctly propagate page faults back
into the guest when we could have either an ordinary page
fault or a nested page fault. In the case of a nested page
fault the fault-address is different from the original
address that should be walked. So we need to keep track
about the real fault-address.
We could also remove the current path of the error_code to
the fault. But this change is too invasive and outside the
scope of this patch set. It will be changed and tested
seperatly.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/kvm/paging_tmpl.h | 4 ++++
2 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d9dfc8c..8426870 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -298,6 +298,9 @@ struct kvm_vcpu_arch {
/* Used for two dimensional paging emulation */
struct kvm_mmu nested_mmu;

+ unsigned long fault_address;
+ int fault_error_code;
+
/* only needed in kvm_pv_mmu_op() path, but it's hot so
* put it here to avoid allocation */
struct kvm_pv_mmu_op_buffer mmu_op_buffer;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 8b27026..df92ce2 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -266,6 +266,10 @@ err:
walker->error_code |= PFERR_FETCH_MASK;
if (rsvd_fault)
walker->error_code |= PFERR_RSVD_MASK;
+
+ vcpu->arch.fault_address = addr;
+ vcpu->arch.fault_error_code = walker->error_code;
+
trace_kvm_mmu_walker_error(walker->error_code);
return 0;
}
--
1.7.0.4