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| author | Quentin Perret <qperret@google.com> | 2022-11-10 22:02:47 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-11-11 20:16:25 +0300 |
| commit | aa6948f82f0b7060fbbac21911dc7996b144ba3c (patch) | |
| tree | 6d16f6fd3b93bdd14027b47005ee913926834f45 /arch/arm64/include/asm/kvm_pgtable.h | |
| parent | 9d0c063a4d1d10ef8e6288899b8524413e40cfa0 (diff) | |
| download | linux-aa6948f82f0b7060fbbac21911dc7996b144ba3c.tar.xz | |
KVM: arm64: Add per-cpu fixmap infrastructure at EL2
Mapping pages in a guest page-table from within the pKVM hypervisor at
EL2 may require cache maintenance to ensure that the initialised page
contents is visible even to non-cacheable (e.g. MMU-off) accesses from
the guest.
In preparation for performing this maintenance at EL2, introduce a
per-vCPU fixmap which allows the pKVM hypervisor to map guest pages
temporarily into its stage-1 page-table for the purposes of cache
maintenance and, in future, poisoning on the reclaim path. The use of a
fixmap avoids the need for memory allocation or locking on the map()
path.
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-15-will@kernel.org
Diffstat (limited to 'arch/arm64/include/asm/kvm_pgtable.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_pgtable.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 15c389db1931..34cb93f3c96d 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -42,6 +42,8 @@ typedef u64 kvm_pte_t; #define KVM_PTE_ADDR_MASK GENMASK(47, PAGE_SHIFT) #define KVM_PTE_ADDR_51_48 GENMASK(15, 12) +#define KVM_PHYS_INVALID (-1ULL) + static inline bool kvm_pte_valid(kvm_pte_t pte) { return pte & KVM_PTE_VALID; @@ -57,6 +59,18 @@ static inline u64 kvm_pte_to_phys(kvm_pte_t pte) return pa; } +static inline kvm_pte_t kvm_phys_to_pte(u64 pa) +{ + kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK; + + if (PAGE_SHIFT == 16) { + pa &= GENMASK(51, 48); + pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48); + } + + return pte; +} + static inline u64 kvm_granule_shift(u32 level) { /* Assumes KVM_PGTABLE_MAX_LEVELS is 4 */ |