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| author | Marc Zyngier <marc.zyngier@arm.com> | 2018-04-06 13:27:28 +0200 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-07-09 12:37:41 +0200 |
| commit | e48d53a91f6e90873e21a5ca5e8c0d7a9f8936a4 (patch) | |
| tree | 8226aa3bd5ae8eefb39ad90d66fff26917bd747b /arch/arm64/include/asm/pgtable-prot.h | |
| parent | Linux 4.18-rc4 (diff) | |
| download | linux-e48d53a91f6e90873e21a5ca5e8c0d7a9f8936a4.tar.xz linux-e48d53a91f6e90873e21a5ca5e8c0d7a9f8936a4.zip | |
arm64: KVM: Add support for Stage-2 control of memory types and cacheability
Up to ARMv8.3, the combinaison of Stage-1 and Stage-2 attributes
results in the strongest attribute of the two stages. This means
that the hypervisor has to perform quite a lot of cache maintenance
just in case the guest has some non-cacheable mappings around.
ARMv8.4 solves this problem by offering a different mode (FWB) where
Stage-2 has total control over the memory attribute (this is limited
to systems where both I/O and instruction fetches are coherent with
the dcache). This is achieved by having a different set of memory
attributes in the page tables, and a new bit set in HCR_EL2.
On such a system, we can then safely sidestep any form of dcache
management.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/pgtable-prot.h')
| -rw-r--r-- | arch/arm64/include/asm/pgtable-prot.h | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index 108ecad7acc5..c66c3047400e 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -67,8 +67,18 @@ #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_S2 __pgprot(_PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY | PTE_S2_XN) -#define PAGE_S2_DEVICE __pgprot(_PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_S2_XN) +#define PAGE_S2_MEMATTR(attr) \ + ({ \ + u64 __val; \ + if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) \ + __val = PTE_S2_MEMATTR(MT_S2_FWB_ ## attr); \ + else \ + __val = PTE_S2_MEMATTR(MT_S2_ ## attr); \ + __val; \ + }) + +#define PAGE_S2 __pgprot(_PROT_DEFAULT | PAGE_S2_MEMATTR(NORMAL) | PTE_S2_RDONLY | PTE_S2_XN) +#define PAGE_S2_DEVICE __pgprot(_PROT_DEFAULT | PAGE_S2_MEMATTR(DEVICE_nGnRE) | PTE_S2_RDONLY | PTE_S2_XN) #define PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE) |