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KVM: s390: vsie: fix virtual/physical address in unpin_scb()

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In commit 77b5334115 ("KVM: s390: VSIE: sort out virtual/physical
address in pin_guest_page"), only pin_scb() has been updated. This
means that in unpin_scb() a virtual address was still used directly as
physical address without conversion. The resulting physical address is
obviously wrong and most of the time also invalid.

Since commit d0ef8d9fbe ("KVM: s390: Use kvm_release_page_dirty() to
unpin "struct page" memory"), unpin_guest_page() will directly use
kvm_release_page_dirty(), instead of kvm_release_pfn_dirty(), which has
since been removed.

One of the checks that were performed by kvm_release_pfn_dirty() was to
verify whether the page was valid at all, and silently return
successfully without doing anything if the page was invalid.

When kvm_release_pfn_dirty() was still used, the invalid page was thus
silently ignored. Now the check is gone and the result is an Oops.
This also means that when running with a V!=R kernel, the page was not
released, causing a leak.

The solution is simply to add the missing virt_to_phys().

Fixes: 77b5334115 ("KVM: s390: VSIE: sort out virtual/physical address in pin_guest_page")
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Link: https://lore.kernel.org/r/20241210083948.23963-1-imbrenda@linux.ibm.com
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20241210083948.23963-1-imbrenda@linux.ibm.com>
This commit is contained in:
Claudio Imbrenda 2024-12-10 09:39:48 +01:00
parent 9d89551994
commit 984aaf6161
1 changed files with 1 additions and 1 deletions
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2
arch/s390/kvm/vsie.c
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@ -854,7 +854,7 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
gpa_t gpa)
{
hpa_t hpa = (hpa_t) vsie_page->scb_o;
hpa_t hpa = virt_to_phys(vsie_page->scb_o);
if (hpa)
unpin_guest_page(vcpu->kvm, gpa, hpa);