From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
This reverts commit 85c8555ff0 ("KVM: check for !is_zero_pfn() in
kvm_is_mmio_pfn()") and renames the function to kvm_is_reserved_pfn.
The problem being addressed by the patch above was that some ARM code
based the memory mapping attributes of a pfn on the return value of
kvm_is_mmio_pfn(), whose name indeed suggests that such pfns should
be mapped as device memory.
However, kvm_is_mmio_pfn() doesn't do quite what it says on the tin,
and the existing non-ARM users were already using it in a way which
suggests that its name should probably have been 'kvm_is_reserved_pfn'
from the beginning, e.g., whether or not to call get_page/put_page on
it etc. This means that returning false for the zero page is a mistake
and the patch above should be reverted.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/ia64/kvm/kvm-ia64.c | 2 +-
arch/x86/kvm/mmu.c | 6 +++---
include/linux/kvm_host.h | 2 +-
virt/kvm/kvm_main.c | 16 ++++++++--------
4 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index ec6b9ac..dbe46f4 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1563,7 +1563,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
for (i = 0; i < npages; i++) {
pfn = gfn_to_pfn(kvm, base_gfn + i);
- if (!kvm_is_mmio_pfn(pfn)) {
+ if (!kvm_is_reserved_pfn(pfn)) {
kvm_set_pmt_entry(kvm, base_gfn + i,
pfn << PAGE_SHIFT,
_PAGE_AR_RWX | _PAGE_MA_WB);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ac1c4de..978f402 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -630,7 +630,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep)
* kvm mmu, before reclaiming the page, we should
* unmap it from mmu first.
*/
- WARN_ON(!kvm_is_mmio_pfn(pfn) && !page_count(pfn_to_page(pfn)));
+ WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn)));
if (!shadow_accessed_mask || old_spte & shadow_accessed_mask)
kvm_set_pfn_accessed(pfn);
@@ -2461,7 +2461,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
spte |= PT_PAGE_SIZE_MASK;
if (tdp_enabled)
spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
- kvm_is_mmio_pfn(pfn));
+ kvm_is_reserved_pfn(pfn));
if (host_writable)
spte |= SPTE_HOST_WRITEABLE;
@@ -2737,7 +2737,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
* PT_PAGE_TABLE_LEVEL and there would be no adjustment done
* here.
*/
- if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn) &&
+ if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) &&
level == PT_PAGE_TABLE_LEVEL &&
PageTransCompound(pfn_to_page(pfn)) &&
!has_wrprotected_page(vcpu->kvm, gfn, PT_DIRECTORY_LEVEL)) {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ea53b04..a6059bd 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -703,7 +703,7 @@ void kvm_arch_sync_events(struct kvm *kvm);
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
-bool kvm_is_mmio_pfn(pfn_t pfn);
+bool kvm_is_reserved_pfn(pfn_t pfn);
struct kvm_irq_ack_notifier {
struct hlist_node link;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 25ffac9..3cee7b1 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -107,10 +107,10 @@ EXPORT_SYMBOL_GPL(kvm_rebooting);
static bool largepages_enabled = true;
-bool kvm_is_mmio_pfn(pfn_t pfn)
+bool kvm_is_reserved_pfn(pfn_t pfn)
{
if (pfn_valid(pfn))
- return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn));
+ return PageReserved(pfn_to_page(pfn));
return true;
}
@@ -1321,7 +1321,7 @@ static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
else if ((vma->vm_flags & VM_PFNMAP)) {
pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
vma->vm_pgoff;
- BUG_ON(!kvm_is_mmio_pfn(pfn));
+ BUG_ON(!kvm_is_reserved_pfn(pfn));
} else {
if (async && vma_is_valid(vma, write_fault))
*async = true;
@@ -1427,7 +1427,7 @@ static struct page *kvm_pfn_to_page(pfn_t pfn)
if (is_error_noslot_pfn(pfn))
return KVM_ERR_PTR_BAD_PAGE;
- if (kvm_is_mmio_pfn(pfn)) {
+ if (kvm_is_reserved_pfn(pfn)) {
WARN_ON(1);
return KVM_ERR_PTR_BAD_PAGE;
}
@@ -1456,7 +1456,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean);
void kvm_release_pfn_clean(pfn_t pfn)
{
- if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn))
+ if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
put_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
@@ -1477,7 +1477,7 @@ static void kvm_release_pfn_dirty(pfn_t pfn)
void kvm_set_pfn_dirty(pfn_t pfn)
{
- if (!kvm_is_mmio_pfn(pfn)) {
+ if (!kvm_is_reserved_pfn(pfn)) {
struct page *page = pfn_to_page(pfn);
if (!PageReserved(page))
SetPageDirty(page);
@@ -1487,14 +1487,14 @@ EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
void kvm_set_pfn_accessed(pfn_t pfn)
{
- if (!kvm_is_mmio_pfn(pfn))
+ if (!kvm_is_reserved_pfn(pfn))
mark_page_accessed(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
void kvm_get_pfn(pfn_t pfn)
{
- if (!kvm_is_mmio_pfn(pfn))
+ if (!kvm_is_reserved_pfn(pfn))
get_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_get_pfn);
--
2.1.2.330.g565301e.dirty
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