* [PATCH v4 1/5] KVM: SEV: Treat unassigned RMP entry as benign race on PSMASH failure
2026-08-26 9:01 [PATCH v4 0/5] Stop returning struct page from guest_memfd PFN lookup Ackerley Tng
@ 2026-08-26 9:01 ` Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 2/5] KVM: SEV: Drop page refcount early during RMP fault handling Ackerley Tng
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Ackerley Tng @ 2026-08-26 9:01 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Ashish Kalra,
Michael Roth, Brijesh Singh, Marc Zyngier, Oliver Upton,
Joey Gouly, Steffen Eiden, Suzuki K Poulose, Zenghui Yu,
Catalin Marinas, Will Deacon, David Hildenbrand, Yan Zhao,
Edgecombe, Rick P, Vishal Annapurve, Fuad Tabba
Cc: kvm, linux-kernel, linux-arm-kernel, kvmarm, Ackerley Tng
When handling an RMP fault, KVM attempts to split a 2MB page via PSMASH.
If PSMASH fails, the only expected return value is FAIL_BADADDR, which does
not distinguish the reason for the bad address. Hence, another RMP entry
lookup is required to determine whether the failure was benign.
Specifically, KVM re-checks the RMP entry to determine if another CPU raced
and already smashed the entry into 4KB pages.
A concurrent operation (such as guest_memfd truncation or hole punching)
can also race and transition the page to shared, removing the page from the
RMP table and causing PSMASH to fail. This can happen even if the page is
still referenced by KVM, because guest_memfd reclaim transitions the RMP
entry to shared when the folio is removed from the page cache.
Treat an unassigned RMP entry as an expected race when re-checking after a
failed PSMASH, and skip logging an error warning.
Fixes: c63cf135cc99 ("KVM: SEV: Add support to handle RMP nested page faults")
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
arch/x86/kvm/svm/sev.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 5705723f1f412..e198469eb074c 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5090,10 +5090,11 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
/*
* Look it up again. If it's 4K now then the PSMASH may have
* raced with another process and the issue has already resolved
- * itself.
+ * itself. If it's not assigned, then this must have raced with
+ * another process that made this page shared.
*/
if (!snp_lookup_rmpentry(pfn, &assigned, &rmp_level) &&
- assigned && rmp_level == PG_LEVEL_4K)
+ ((assigned && rmp_level == PG_LEVEL_4K) || !assigned))
goto out;
pr_warn_ratelimited("SEV: Unable to split RMP entry for GPA 0x%llx PFN 0x%llx ret %d\n",
--
2.55.0.887.g758fc8c411-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v4 2/5] KVM: SEV: Drop page refcount early during RMP fault handling
2026-08-26 9:01 [PATCH v4 0/5] Stop returning struct page from guest_memfd PFN lookup Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 1/5] KVM: SEV: Treat unassigned RMP entry as benign race on PSMASH failure Ackerley Tng
@ 2026-08-26 9:01 ` Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 3/5] KVM: SEV: Check for invalidation before warning on unassigned RMP entry Ackerley Tng
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Ackerley Tng @ 2026-08-26 9:01 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Ashish Kalra,
Michael Roth, Brijesh Singh, Marc Zyngier, Oliver Upton,
Joey Gouly, Steffen Eiden, Suzuki K Poulose, Zenghui Yu,
Catalin Marinas, Will Deacon, David Hildenbrand, Yan Zhao,
Edgecombe, Rick P, Vishal Annapurve, Fuad Tabba
Cc: kvm, linux-kernel, linux-arm-kernel, kvmarm, Ackerley Tng
From: Sean Christopherson <seanjc@google.com>
Rework KVM's handling of RMP faults to rely on MMU invalidation logic for
safety, instead of the current approach of holding onto a folio reference
until the RMP operations are complete. I.e. drop the reference gifted by
guest_memfd immediately after getting the PFN, and instead do RMP updates
under mmu_lock, after checking for relevant MMU invalidations.
This will allow dropping guest_memfd's reference gifting entirely, which is
ideally how KVM would operate for all "follow PFN" operations (GUP has many
more complications, which is why KVM holds a reference across page
faults *on top* of the standard MMU invalidation logic).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Co-developed-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
arch/x86/kvm/svm/sev.c | 39 ++++++++++++++++++++++++---------------
1 file changed, 24 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index e198469eb074c..0d027cff734cf 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5019,6 +5019,7 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
struct kvm_memory_slot *slot;
struct kvm *kvm = vcpu->kvm;
int order, rmp_level, ret;
+ unsigned long mmu_seq;
struct page *page;
bool assigned;
kvm_pfn_t pfn;
@@ -5046,18 +5047,22 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
return;
}
+ mmu_seq = kvm->mmu_invalidate_seq;
+ smp_rmb();
+
ret = kvm_gmem_get_pfn(kvm, slot, gfn, &pfn, &page, &order);
if (ret) {
pr_warn_ratelimited("SEV: Unexpected RMP fault, no backing page for private GPA 0x%llx\n",
gpa);
return;
}
+ kvm_release_page_unused(page);
ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
if (ret || !assigned) {
pr_warn_ratelimited("SEV: Unexpected RMP fault, no assigned RMP entry found for GPA 0x%llx PFN 0x%llx error %d\n",
gpa, pfn, ret);
- goto out_no_trace;
+ return;
}
/*
@@ -5085,27 +5090,31 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
if (rmp_level == PG_LEVEL_4K)
goto out;
- ret = snp_rmptable_psmash(pfn);
- if (ret) {
- /*
- * Look it up again. If it's 4K now then the PSMASH may have
- * raced with another process and the issue has already resolved
- * itself. If it's not assigned, then this must have raced with
- * another process that made this page shared.
- */
- if (!snp_lookup_rmpentry(pfn, &assigned, &rmp_level) &&
- ((assigned && rmp_level == PG_LEVEL_4K) || !assigned))
+ scoped_guard(read_lock, &kvm->mmu_lock) {
+ if (mmu_invalidate_retry_gfn(kvm, mmu_seq, gfn))
goto out;
- pr_warn_ratelimited("SEV: Unable to split RMP entry for GPA 0x%llx PFN 0x%llx ret %d\n",
- gpa, pfn, ret);
+ ret = snp_rmptable_psmash(pfn);
+ if (ret) {
+ /*
+ * Look it up again. If it's 4K now then the PSMASH may
+ * have raced with another process and the issue has
+ * already resolved itself. If it's not assigned, then
+ * this must have raced with another process that made
+ * this page shared.
+ */
+ if (!snp_lookup_rmpentry(pfn, &assigned, &rmp_level) &&
+ ((assigned && rmp_level == PG_LEVEL_4K) || !assigned))
+ goto out;
+
+ pr_warn_ratelimited("SEV: Unable to split RMP entry for GPA 0x%llx PFN 0x%llx ret %d\n",
+ gpa, pfn, ret);
+ }
}
kvm_zap_gfn_range(kvm, gfn, gfn + PTRS_PER_PMD);
out:
trace_kvm_rmp_fault(vcpu, gpa, pfn, error_code, rmp_level, ret);
-out_no_trace:
- kvm_release_page_unused(page);
}
static bool is_pfn_range_shared(kvm_pfn_t start, kvm_pfn_t end)
--
2.55.0.887.g758fc8c411-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v4 3/5] KVM: SEV: Check for invalidation before warning on unassigned RMP entry
2026-08-26 9:01 [PATCH v4 0/5] Stop returning struct page from guest_memfd PFN lookup Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 1/5] KVM: SEV: Treat unassigned RMP entry as benign race on PSMASH failure Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 2/5] KVM: SEV: Drop page refcount early during RMP fault handling Ackerley Tng
@ 2026-08-26 9:01 ` Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 4/5] KVM: SEV: Drop page refcount early in VMSA reload Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 5/5] KVM: guest_memfd: Stop returning struct page from PFN lookup Ackerley Tng
4 siblings, 0 replies; 6+ messages in thread
From: Ackerley Tng @ 2026-08-26 9:01 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Ashish Kalra,
Michael Roth, Brijesh Singh, Marc Zyngier, Oliver Upton,
Joey Gouly, Steffen Eiden, Suzuki K Poulose, Zenghui Yu,
Catalin Marinas, Will Deacon, David Hildenbrand, Yan Zhao,
Edgecombe, Rick P, Vishal Annapurve, Fuad Tabba
Cc: kvm, linux-kernel, linux-arm-kernel, kvmarm, Ackerley Tng
When handling an RMP fault, KVM looks up the RMP entry for the backing
PFN to determine if a 2MB page needs to be split via PSMASH. If the RMP
entry is not assigned (or lookup fails), KVM logs a rate-limited warning
under the assumption that private memory should always have an assigned
RMP entry.
However, a concurrent invalidation (such as guest_memfd hole punching) can
race with RMP fault handling and transition the page to shared, unassigning
the RMP entry after KVM fetched the PFN. In such cases, not finding an
assigned RMP entry is benign.
Check mmu_invalidate_retry_gfn() under mmu_lock before warning about a
missing or unassigned RMP entry, and suppress the spurious warning if an
invalidation occurred for the faulting GFN.
Fixes: c63cf135cc99 ("KVM: SEV: Add support to handle RMP nested page faults")
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
arch/x86/kvm/svm/sev.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 0d027cff734cf..f9dce8acac8eb 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5060,8 +5060,12 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
if (ret || !assigned) {
- pr_warn_ratelimited("SEV: Unexpected RMP fault, no assigned RMP entry found for GPA 0x%llx PFN 0x%llx error %d\n",
- gpa, pfn, ret);
+ guard(read_lock)(&kvm->mmu_lock);
+
+ if (!mmu_invalidate_retry_gfn(kvm, mmu_seq, gfn))
+ pr_warn_ratelimited("SEV: Unexpected RMP fault, no assigned RMP entry found for GPA 0x%llx PFN 0x%llx error %d\n",
+ gpa, pfn, ret);
+
return;
}
--
2.55.0.887.g758fc8c411-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v4 4/5] KVM: SEV: Drop page refcount early in VMSA reload
2026-08-26 9:01 [PATCH v4 0/5] Stop returning struct page from guest_memfd PFN lookup Ackerley Tng
` (2 preceding siblings ...)
2026-08-26 9:01 ` [PATCH v4 3/5] KVM: SEV: Check for invalidation before warning on unassigned RMP entry Ackerley Tng
@ 2026-08-26 9:01 ` Ackerley Tng
2026-08-26 9:01 ` [PATCH v4 5/5] KVM: guest_memfd: Stop returning struct page from PFN lookup Ackerley Tng
4 siblings, 0 replies; 6+ messages in thread
From: Ackerley Tng @ 2026-08-26 9:01 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Ashish Kalra,
Michael Roth, Brijesh Singh, Marc Zyngier, Oliver Upton,
Joey Gouly, Steffen Eiden, Suzuki K Poulose, Zenghui Yu,
Catalin Marinas, Will Deacon, David Hildenbrand, Yan Zhao,
Edgecombe, Rick P, Vishal Annapurve, Fuad Tabba
Cc: kvm, linux-kernel, linux-arm-kernel, kvmarm, Ackerley Tng
When reloading the guest VMSA for an SEV-SNP vCPU, KVM retrieves the PFN
from guest_memfd.
Drop the page reference immediately after retrieving the PFN instead of
holding it across MMU lock acquisition in preparation for a follow-up patch
to stop returning page pointers from guest_memfd PFN lookups.
This is safe because the page's validity and presence are governed by KVM's
MMU invalidation protocol rather than the page reference.
No functional change intended.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
arch/x86/kvm/svm/sev.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index f9dce8acac8eb..f094b19226b92 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -4078,6 +4078,7 @@ static void __sev_snp_reload_vmsa(struct kvm_vcpu *vcpu, gpa_t gpa)
*/
if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, &page, NULL))
return;
+ kvm_release_page_clean(page);
read_lock(&kvm->mmu_lock);
/*
@@ -4092,8 +4093,6 @@ static void __sev_snp_reload_vmsa(struct kvm_vcpu *vcpu, gpa_t gpa)
else
svm->vmcb->control.vmsa_pa = pfn_to_hpa(pfn);
read_unlock(&kvm->mmu_lock);
-
- kvm_release_page_clean(page);
}
/*
--
2.55.0.887.g758fc8c411-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v4 5/5] KVM: guest_memfd: Stop returning struct page from PFN lookup
2026-08-26 9:01 [PATCH v4 0/5] Stop returning struct page from guest_memfd PFN lookup Ackerley Tng
` (3 preceding siblings ...)
2026-08-26 9:01 ` [PATCH v4 4/5] KVM: SEV: Drop page refcount early in VMSA reload Ackerley Tng
@ 2026-08-26 9:01 ` Ackerley Tng
4 siblings, 0 replies; 6+ messages in thread
From: Ackerley Tng @ 2026-08-26 9:01 UTC (permalink / raw)
To: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Ashish Kalra,
Michael Roth, Brijesh Singh, Marc Zyngier, Oliver Upton,
Joey Gouly, Steffen Eiden, Suzuki K Poulose, Zenghui Yu,
Catalin Marinas, Will Deacon, David Hildenbrand, Yan Zhao,
Edgecombe, Rick P, Vishal Annapurve, Fuad Tabba
Cc: kvm, linux-kernel, linux-arm-kernel, kvmarm, Ackerley Tng
From: Sean Christopherson <seanjc@google.com>
KVM currently expects guest_memfd PFN lookups to return a refcounted struct
page, which callers hold across fault handling.
Drop the page's refcount before returning from kvm_gmem_get_pfn() to
prepare for the in-place conversions series.
CoCo shared-to-private conversion handling must inspect folio refcounts to
ensure exclusive ownership by guest_memfd. A concurrent guest page fault
taking a temporary reference on the folio causes conversions to fail due to
an elevated refcount.
While this refcount is also taken on host userspace page faults, that
refcount is taken on behalf of the host userspace page tables. This
refcount will be dropped when conversions unmaps the page. Either way, once
there's an mmap() or userspace mapping, the pages are open to way more
refcounts, transient or not. This patch focuses on just dropping refcounts
before handing KVM a page.
guest_memfd already notifies KVM of page invalidations, so callers within
KVM only need to respect the MMU invalidation protocol to safely rely on
guest_memfd for page presence.
Since the page refcounts are dropped, don't return the struct page pointer.
Not returning the struct page from the guest_memfd PFN lookup moves KVM
closer toward supporting memory backends that are not backed by struct
page.
Here are some notes on the cleanup in the callers of kvm_gmem_get_pfn():
kvm_release_faultin_page() in ARM's gmem_abort() originally also serves to
set the page dirty and accessed under some conditions. The dirty and
accessed flags don't matter for guest_memfd anyway, so it is safe to just
drop the call to kvm_release_faultin_page().
For ARM's kvm_translate_vncr(), the local page pointer must be initialized
to NULL so that the shared cleanup path that releases faulted-in pages
safely no-ops for guest_memfd.
For x86, no additional changes are required in the MMU fault path because
the page fault tracking structure is zero-initialized at the start of page
fault handling, ensuring the refcounted page pointer is already NULL.
Reported-by: Yan Zhao <yan.y.zhao@intel.com>
Closes: https://lore.kernel.org/all/anZ4W9o5pTWIEgMY@yzhao56-desk.sh.intel.com/
Signed-off-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Tested-by: Michael Roth <michael.roth@amd.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Co-developed-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
arch/arm64/kvm/mmu.c | 4 +---
arch/arm64/kvm/nested.c | 4 ++--
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/svm/sev.c | 8 ++------
include/linux/kvm_host.h | 6 ++----
virt/kvm/guest_memfd.c | 9 ++-------
6 files changed, 10 insertions(+), 23 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 9ba86450fe4af..d57f8181f1b7d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1613,7 +1613,6 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
struct kvm_pgtable *pgt = s2fd->vcpu->arch.hw_mmu->pgt;
unsigned long mmu_seq;
- struct page *page;
struct kvm *kvm = s2fd->vcpu->kvm;
void *memcache = NULL;
kvm_pfn_t pfn;
@@ -1641,7 +1640,7 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
/* Pairs with the smp_wmb() in kvm_mmu_invalidate_end(). */
smp_rmb();
- ret = kvm_gmem_get_pfn(kvm, s2fd->memslot, gfn, &pfn, &page, NULL);
+ ret = kvm_gmem_get_pfn(kvm, s2fd->memslot, gfn, &pfn, NULL);
if (ret) {
kvm_prepare_memory_fault_exit(s2fd->vcpu, s2fd->fault_ipa, PAGE_SIZE,
write_fault, exec_fault, false);
@@ -1681,7 +1680,6 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
}
out_unlock:
- kvm_release_faultin_page(kvm, page, !!ret, prot & KVM_PGTABLE_PROT_W);
kvm_fault_unlock(kvm);
if ((prot & KVM_PGTABLE_PROT_W) && !ret)
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 17123f0b6daba..dd62840d36741 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1415,7 +1415,7 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
bool write_fault, writable;
unsigned long mmu_seq;
struct vncr_tlb *vt;
- struct page *page;
+ struct page *page = NULL;
u64 va, pfn, gfn;
int ret;
@@ -1471,7 +1471,7 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
return -EFAULT;
}
} else {
- ret = kvm_gmem_get_pfn(vcpu->kvm, memslot, gfn, &pfn, &page, NULL);
+ ret = kvm_gmem_get_pfn(vcpu->kvm, memslot, gfn, &pfn, NULL);
if (ret) {
kvm_prepare_memory_fault_exit(vcpu, vt->wr.pa, PAGE_SIZE,
write_fault, false, false);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 064ecc33b9267..947c9cd843450 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4628,7 +4628,7 @@ static int kvm_mmu_faultin_pfn_gmem(struct kvm_vcpu *vcpu,
}
r = kvm_gmem_get_pfn(vcpu->kvm, fault->slot, fault->gfn, &fault->pfn,
- &fault->refcounted_page, &max_order);
+ &max_order);
if (r) {
kvm_mmu_prepare_memory_fault_exit(vcpu, fault);
return r;
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index f094b19226b92..0a887f8e05d3a 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -4032,7 +4032,6 @@ static void __sev_snp_reload_vmsa(struct kvm_vcpu *vcpu, gpa_t gpa)
struct kvm *kvm = vcpu->kvm;
gfn_t gfn = gpa_to_gfn(gpa);
unsigned long mmu_seq;
- struct page *page;
kvm_pfn_t pfn;
lockdep_assert_held(&svm->sev_es.snp_vmsa_mutex);
@@ -4076,9 +4075,8 @@ static void __sev_snp_reload_vmsa(struct kvm_vcpu *vcpu, gpa_t gpa)
* The new VMSA will be private memory guest memory, so retrieve the
* PFN from the gmem backend.
*/
- if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, &page, NULL))
+ if (kvm_gmem_get_pfn(vcpu->kvm, slot, gfn, &pfn, NULL))
return;
- kvm_release_page_clean(page);
read_lock(&kvm->mmu_lock);
/*
@@ -5019,7 +5017,6 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
struct kvm *kvm = vcpu->kvm;
int order, rmp_level, ret;
unsigned long mmu_seq;
- struct page *page;
bool assigned;
kvm_pfn_t pfn;
gfn_t gfn;
@@ -5049,13 +5046,12 @@ void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
mmu_seq = kvm->mmu_invalidate_seq;
smp_rmb();
- ret = kvm_gmem_get_pfn(kvm, slot, gfn, &pfn, &page, &order);
+ ret = kvm_gmem_get_pfn(kvm, slot, gfn, &pfn, &order);
if (ret) {
pr_warn_ratelimited("SEV: Unexpected RMP fault, no backing page for private GPA 0x%llx\n",
gpa);
return;
}
- kvm_release_page_unused(page);
ret = snp_lookup_rmpentry(pfn, &assigned, &rmp_level);
if (ret || !assigned) {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 03bfc92864b6e..502465119ca0c 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2586,13 +2586,11 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
#ifdef CONFIG_KVM_GUEST_MEMFD
int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
- gfn_t gfn, kvm_pfn_t *pfn, struct page **page,
- int *max_order);
+ gfn_t gfn, kvm_pfn_t *pfn, int *max_order);
#else
static inline int kvm_gmem_get_pfn(struct kvm *kvm,
struct kvm_memory_slot *slot, gfn_t gfn,
- kvm_pfn_t *pfn, struct page **page,
- int *max_order)
+ kvm_pfn_t *pfn, int *max_order)
{
KVM_BUG_ON(1, kvm);
return -EIO;
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index b596486d184ca..589762140c3ef 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -751,8 +751,7 @@ static struct folio *__kvm_gmem_get_pfn(struct file *file,
}
int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
- gfn_t gfn, kvm_pfn_t *pfn, struct page **page,
- int *max_order)
+ gfn_t gfn, kvm_pfn_t *pfn, int *max_order)
{
pgoff_t index = kvm_gmem_get_index(slot, gfn);
struct folio *folio;
@@ -780,11 +779,7 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
#endif
folio_unlock(folio);
-
- if (!r)
- *page = folio_file_page(folio, index);
- else
- folio_put(folio);
+ folio_put(folio);
return r;
}
--
2.55.0.887.g758fc8c411-goog
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