KVM: arm64: Fix definition of PAGE_HYP_DEVICE

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.
Acked-by: Marc Zyngier <maz@kernel.org>
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>
Link: https://lore.kernel.org/r/20200708162546.26176-1-will@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>

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)						\
 	({								\