[PATCH AUTOSEL 4.14 42/95] KVM: arm/arm64: Ensure only THP is candidate for adjustment

[PATCH AUTOSEL 4.14 42/95] KVM: arm/arm64: Ensure only THP is candidate for adjustment

[Sasha Levin]

From: Punit Agrawal <punit.agrawal@arm.com>

[ Upstream commit fd2ef358282c849c193aa36dadbf4f07f7dcd29b ]

PageTransCompoundMap() returns true for hugetlbfs and THP
hugepages. This behaviour incorrectly leads to stage 2 faults for
unsupported hugepage sizes (e.g., 64K hugepage with 4K pages) to be
treated as THP faults.

Tighten the check to filter out hugetlbfs pages. This also leads to
consistently mapping all unsupported hugepage sizes as PTE level
entries at stage 2.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 virt/kvm/arm/mmu.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 225dc671ae31..1f4cac53b923 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1068,8 +1068,14 @@ static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
 {
 	kvm_pfn_t pfn = *pfnp;
 	gfn_t gfn = *ipap >> PAGE_SHIFT;
+	struct page *page = pfn_to_page(pfn);
 
-	if (PageTransCompoundMap(pfn_to_page(pfn))) {
+	/*
+	 * PageTransCompoungMap() returns true for THP and
+	 * hugetlbfs. Make sure the adjustment is done only for THP
+	 * pages.
+	 */
+	if (!PageHuge(page) && PageTransCompoundMap(page)) {
 		unsigned long mask;
 		/*
 		 * The address we faulted on is backed by a transparent huge
-- 
2.20.1

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[PATCH AUTOSEL 4.14 63/95] arm64: KVM: Make VHE Stage-2 TLB invalidation operations non-interruptible

[Sasha Levin]

From: Marc Zyngier <marc.zyngier@arm.com>

[ Upstream commit c987876a80e7bcb98a839f10dca9ce7fda4feced ]

Contrary to the non-VHE version of the TLB invalidation helpers, the VHE
code  has interrupts enabled, meaning that we can take an interrupt in
the middle of such a sequence, and start running something else with
HCR_EL2.TGE cleared.

That's really not a good idea.

Take the heavy-handed option and disable interrupts in
__tlb_switch_to_guest_vhe, restoring them in __tlb_switch_to_host_vhe.
The latter also gain an ISB in order to make sure that TGE really has
taken effect.

Cc: stable@vger.kernel.org
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 arch/arm64/kvm/hyp/tlb.c | 35 +++++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c
index 73464a96c365..db23c6e5c885 100644
--- a/arch/arm64/kvm/hyp/tlb.c
+++ b/arch/arm64/kvm/hyp/tlb.c
@@ -15,13 +15,18 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/irqflags.h>
+
 #include <asm/kvm_hyp.h>
 #include <asm/tlbflush.h>
 
-static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)
+static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
+						 unsigned long *flags)
 {
 	u64 val;
 
+	local_irq_save(*flags);
+
 	/*
 	 * With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and
 	 * most TLB operations target EL2/EL0. In order to affect the
@@ -36,7 +41,8 @@ static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm)
 	isb();
 }
 
-static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm)
+static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,
+						  unsigned long *flags)
 {
 	write_sysreg(kvm->arch.vttbr, vttbr_el2);
 	isb();
@@ -47,7 +53,8 @@ static hyp_alternate_select(__tlb_switch_to_guest,
 			    __tlb_switch_to_guest_vhe,
 			    ARM64_HAS_VIRT_HOST_EXTN);
 
-static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)
+static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,
+						unsigned long flags)
 {
 	/*
 	 * We're done with the TLB operation, let's restore the host's
@@ -55,9 +62,12 @@ static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm)
 	 */
 	write_sysreg(0, vttbr_el2);
 	write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
+	isb();
+	local_irq_restore(flags);
 }
 
-static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm)
+static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,
+						 unsigned long flags)
 {
 	write_sysreg(0, vttbr_el2);
 }
@@ -69,11 +79,13 @@ static hyp_alternate_select(__tlb_switch_to_host,
 
 void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
 {
+	unsigned long flags;
+
 	dsb(ishst);
 
 	/* Switch to requested VMID */
 	kvm = kern_hyp_va(kvm);
-	__tlb_switch_to_guest()(kvm);
+	__tlb_switch_to_guest()(kvm, &flags);
 
 	/*
 	 * We could do so much better if we had the VA as well.
@@ -116,36 +128,39 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
 	if (!has_vhe() && icache_is_vpipt())
 		__flush_icache_all();
 
-	__tlb_switch_to_host()(kvm);
+	__tlb_switch_to_host()(kvm, flags);
 }
 
 void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
 {
+	unsigned long flags;
+
 	dsb(ishst);
 
 	/* Switch to requested VMID */
 	kvm = kern_hyp_va(kvm);
-	__tlb_switch_to_guest()(kvm);
+	__tlb_switch_to_guest()(kvm, &flags);
 
 	__tlbi(vmalls12e1is);
 	dsb(ish);
 	isb();
 
-	__tlb_switch_to_host()(kvm);
+	__tlb_switch_to_host()(kvm, flags);
 }
 
 void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);
+	unsigned long flags;
 
 	/* Switch to requested VMID */
-	__tlb_switch_to_guest()(kvm);
+	__tlb_switch_to_guest()(kvm, &flags);
 
 	__tlbi(vmalle1);
 	dsb(nsh);
 	isb();
 
-	__tlb_switch_to_host()(kvm);
+	__tlb_switch_to_host()(kvm, flags);
 }
 
 void __hyp_text __kvm_flush_vm_context(void)
-- 
2.20.1

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