diff options
author | Marc Zyngier <maz@kernel.org> | 2021-08-06 14:31:08 +0300 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2021-08-20 11:12:24 +0300 |
commit | cf364e08ea1c5dd217afb658d510aaef7d0cc6f4 (patch) | |
tree | 73d252192060ec25e5dce98cc87edfdfdd7cf1b9 /arch/arm64/include/asm/kvm_mmu.h | |
parent | 4efc0ede4f31d7ec25c3dee0c8f07f93735cee6d (diff) | |
download | linux-cf364e08ea1c5dd217afb658d510aaef7d0cc6f4.tar.xz |
KVM: arm64: Upgrade VMID accesses to {READ,WRITE}_ONCE
Since TLB invalidation can run in parallel with VMID allocation,
we need to be careful and avoid any sort of load/store tearing.
Use {READ,WRITE}_ONCE consistently to avoid any surprise.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jade Alglave <jade.alglave@arm.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210806113109.2475-6-will@kernel.org
Diffstat (limited to 'arch/arm64/include/asm/kvm_mmu.h')
-rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 08bc81f6944b..02d378887743 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -252,6 +252,11 @@ static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa, #define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr) +/* + * When this is (directly or indirectly) used on the TLB invalidation + * path, we rely on a previously issued DSB so that page table updates + * and VMID reads are correctly ordered. + */ static __always_inline u64 kvm_get_vttbr(struct kvm_s2_mmu *mmu) { struct kvm_vmid *vmid = &mmu->vmid; @@ -259,7 +264,7 @@ static __always_inline u64 kvm_get_vttbr(struct kvm_s2_mmu *mmu) u64 cnp = system_supports_cnp() ? VTTBR_CNP_BIT : 0; baddr = mmu->pgd_phys; - vmid_field = (u64)vmid->vmid << VTTBR_VMID_SHIFT; + vmid_field = (u64)READ_ONCE(vmid->vmid) << VTTBR_VMID_SHIFT; return kvm_phys_to_vttbr(baddr) | vmid_field | cnp; } |