From ab510027dc4dbd1eeb611a34b0cda8b21fcde492 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Tue, 31 Jul 2018 14:08:57 +0100 Subject: [PATCH] arm64: KVM: Enable Common Not Private translations We rely on cpufeature framework to detect and enable CNP so for KVM we need to patch hyp to set CNP bit just before TTBR0_EL2 gets written. For the guest we encode CNP bit while building vttbr, so we don't need to bother with that in a world switch. Reviewed-by: James Morse Acked-by: Catalin Marinas Acked-by: Marc Zyngier Signed-off-by: Vladimir Murzin Signed-off-by: Catalin Marinas --- arch/arm/include/asm/kvm_arm.h | 1 + arch/arm/include/asm/kvm_mmu.h | 5 +++++ arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/include/asm/kvm_mmu.h | 5 +++++ arch/arm64/kvm/hyp-init.S | 3 +++ virt/kvm/arm/arm.c | 4 ++-- 6 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index 3ab8b3781bfe..2d43dca29c72 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -161,6 +161,7 @@ #else #define VTTBR_X (5 - KVM_T0SZ) #endif +#define VTTBR_CNP_BIT _AC(1, UL) #define VTTBR_BADDR_MASK (((_AC(1, ULL) << (40 - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT _AC(48, ULL) #define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 265ea9cf7df7..847f01fa429d 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -355,6 +355,11 @@ static inline int hyp_map_aux_data(void) #define kvm_phys_to_vttbr(addr) (addr) +static inline bool kvm_cpu_has_cnp(void) +{ + return false; +} + #endif /* !__ASSEMBLY__ */ #endif /* __ARM_KVM_MMU_H__ */ diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index aa45df752a16..b476bc46f0ab 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -175,6 +175,7 @@ #define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN_FLAGS) #define VTTBR_X (VTTBR_X_TGRAN_MAGIC - VTCR_EL2_T0SZ_IPA) +#define VTTBR_CNP_BIT (UL(1)) #define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT (UL(48)) #define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index d6fff7de5539..64337afbf124 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -517,5 +517,10 @@ static inline int hyp_map_aux_data(void) #define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr) +static inline bool kvm_cpu_has_cnp(void) +{ + return system_supports_cnp(); +} + #endif /* __ASSEMBLY__ */ #endif /* __ARM64_KVM_MMU_H__ */ diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S index ea9225160786..4576b86a5579 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -65,6 +65,9 @@ __do_hyp_init: b.lo __kvm_handle_stub_hvc phys_to_ttbr x4, x0 +alternative_if ARM64_HAS_CNP + orr x4, x4, #TTBR_CNP_BIT +alternative_else_nop_endif msr ttbr0_el2, x4 mrs x4, tcr_el1 diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index c92053bc3f96..150c8a69cdaf 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -496,7 +496,7 @@ static bool need_new_vmid_gen(struct kvm *kvm) static void update_vttbr(struct kvm *kvm) { phys_addr_t pgd_phys; - u64 vmid; + u64 vmid, cnp = kvm_cpu_has_cnp() ? VTTBR_CNP_BIT : 0; bool new_gen; read_lock(&kvm_vmid_lock); @@ -546,7 +546,7 @@ static void update_vttbr(struct kvm *kvm) pgd_phys = virt_to_phys(kvm->arch.pgd); BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK); vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK(kvm_vmid_bits); - kvm->arch.vttbr = kvm_phys_to_vttbr(pgd_phys) | vmid; + kvm->arch.vttbr = kvm_phys_to_vttbr(pgd_phys) | vmid | cnp; write_unlock(&kvm_vmid_lock); } -- 2.30.2