[PATCH] KVM: arm64: Fix definition of PAGE_HYP_DEVICE

* [PATCH] KVM: arm64: Fix definition of PAGE_HYP_DEVICE
@ 2020-07-08 16:25 ` Will Deacon
  0 siblings, 0 replies; 9+ messages in thread
From: Will Deacon @ 2020-07-08 16:25 UTC (permalink / raw)
  To: linux-arm-kernel
  Cc: kvmarm, kernel-team, Will Deacon, Marc Zyngier, Catalin Marinas,
	James Morse, stable

PAGE_HYP_DEVICE is intended to encode attribute bits for an EL2 stage-1
pte mapping a device. Unfortunately, it includes PROT_DEVICE_nGnRE which
encodes attributes for EL1 stage-1 mappings such as UXN and nG, which are
RES0 for EL2, and DBM which is meaningless as TCR_EL2.HD is not set.

Fix the definition of PAGE_HYP_DEVICE so that it doesn't set RES0 bits
at EL2.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
Marc -- I'm happy to take this as a fix via arm64 with your Ack.
Please just let me know.

 arch/arm64/include/asm/pgtable-prot.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 2e7e0f452301..4d867c6446c4 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -67,7 +67,7 @@ extern bool arm64_use_ng_mappings;
 #define PAGE_HYP		__pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_HYP_XN)
 #define PAGE_HYP_EXEC		__pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY)
 #define PAGE_HYP_RO		__pgprot(_HYP_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY | PTE_HYP_XN)
-#define PAGE_HYP_DEVICE		__pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
+#define PAGE_HYP_DEVICE		__pgprot(_PROT_DEFAULT | PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_HYP | PTE_HYP_XN)
 
 #define PAGE_S2_MEMATTR(attr)						\
 	({								\
-- 
2.27.0.383.g050319c2ae-goog


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