From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Introduce a helper function to call the KVM fault handler. It allows a new
ioctl to invoke the KVM fault handler to populate without seeing RET_PF_*
enums or other KVM MMU internal definitions because RET_PF_* are internal
to x86 KVM MMU. The implementation is restricted to two-dimensional paging
for simplicity. The shadow paging uses GVA for faulting instead of L1 GPA.
It makes the API difficult to use.
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
v2:
- Make the helper function two-dimensional paging specific. (David)
- Return error when vcpu is in guest mode. (David)
- Rename goal_level to level in kvm_tdp_mmu_map_page(). (Sean)
- Update return code conversion. Don't check pfn.
RET_PF_EMULATE => EINVAL, RET_PF_CONTINUE => EIO (Sean)
- Add WARN_ON_ONCE on RET_PF_CONTINUE and RET_PF_INVALID. (Sean)
- Drop unnecessary EXPORT_SYMBOL_GPL(). (Sean)
---
arch/x86/kvm/mmu.h | 3 +++
arch/x86/kvm/mmu/mmu.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index e8b620a85627..51ff4f67e115 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -183,6 +183,9 @@ static inline void kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu,
__kvm_mmu_refresh_passthrough_bits(vcpu, mmu);
}
+int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code,
+ u8 *level);
+
/*
* Check if a given access (described through the I/D, W/R and U/S bits of a
* page fault error code pfec) causes a permission fault with the given PTE
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 91dd4c44b7d8..a34f4af44cbd 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4687,6 +4687,38 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
return direct_page_fault(vcpu, fault);
}
+int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code,
+ u8 *level)
+{
+ int r;
+
+ /* Restrict to TDP page fault. */
+ if (vcpu->arch.mmu->page_fault != kvm_tdp_page_fault)
+ return -EINVAL;
+
+ r = __kvm_mmu_do_page_fault(vcpu, gpa, error_code, false, NULL, level);
+ if (r < 0)
+ return r;
+
+ switch (r) {
+ case RET_PF_RETRY:
+ return -EAGAIN;
+
+ case RET_PF_FIXED:
+ case RET_PF_SPURIOUS:
+ return 0;
+
+ case RET_PF_EMULATE:
+ return -EINVAL;
+
+ case RET_PF_CONTINUE:
+ case RET_PF_INVALID:
+ default:
+ WARN_ON_ONCE(r);
+ return -EIO;
+ }
+}
+
static void nonpaging_init_context(struct kvm_mmu *context)
{
context->page_fault = nonpaging_page_fault;
--
2.43.2
