On 17/06/2024 04:33, Michael Kelley wrote:
From: Steven Price <steven.price@xxxxxxx> Sent: Wednesday, June 5, 2024 2:30 AM
From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Device mappings (currently) need to be emulated by the VMM so must be
mapped shared with the host.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
arch/arm64/include/asm/pgtable.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 11d614d83317..c986fde262c0 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -644,7 +644,7 @@ static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
#define pgprot_writecombine(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
#define pgprot_device(prot) \
- __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
+ __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN | PROT_NS_SHARED)
#define pgprot_tagged(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED))
#define pgprot_mhp pgprot_tagged
In v2 of the patches, Catalin raised a question about the need for
pgprot_decrypted(). What was concluded? It still looks to me like
pgprot_decrypted() and prot_encrypted() are needed, by
dma_direct_mmap() and remap_oldmem_pfn_range(), respectively.
Also, assuming Hyper-V supports CCA at some point, the Linux guest
drivers for Hyper-V need pgprot_decrypted() in hv_ringbuffer_init().
Right, I think we could simply do :
diff --git a/arch/arm64/include/asm/pgtable.h
b/arch/arm64/include/asm/pgtable.h
index c986fde262c0..1ed45893d1e6 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -648,6 +648,10 @@ static inline void set_pud_at(struct mm_struct *mm,
unsigned long addr,
#define pgprot_tagged(prot) \
__pgprot_modify(prot, PTE_ATTRINDX_MASK,
PTE_ATTRINDX(MT_NORMAL_TAGGED))
#define pgprot_mhp pgprot_tagged
+
+#define pgprot_decrypted(prot) __pgprot_modify(prot, PROT_NS_SHARED,
PROT_NS_SHARED)
+#define pgprot_encrypted(prot) __pgprot_modify(prot, PROT_NS_SHARED, 0)
+
Suzuki
