From mboxrd@z Thu Jan 1 00:00:00 1970 From: vladimir.murzin@arm.com (Vladimir Murzin) Date: Fri, 18 May 2018 10:46:04 +0100 Subject: [PATCH v3 2/3] arm64: KVM: Enable Common Not Private translations In-Reply-To: <1526636765-11289-1-git-send-email-vladimir.murzin@arm.com> References: <1526636765-11289-1-git-send-email-vladimir.murzin@arm.com> Message-ID: <1526636765-11289-3-git-send-email-vladimir.murzin@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Signed-off-by: Vladimir Murzin --- arch/arm/include/asm/kvm_mmu.h | 5 +++++ arch/arm64/include/asm/kvm_mmu.h | 5 +++++ arch/arm64/kvm/hyp-init.S | 3 +++ virt/kvm/arm/arm.c | 4 ++-- 4 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index de1b919..7a9d614 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -307,6 +307,11 @@ static inline int kvm_map_vectors(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_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 7faed6e..f8149d4 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -388,5 +388,10 @@ static inline int kvm_map_vectors(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 5aa9ccf..2e7a93a 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -64,6 +64,9 @@ __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 97d0ab2..a538ba3 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -470,7 +470,7 @@ 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() ? 1 : 0; if (!need_new_vmid_gen(kvm)) return; @@ -522,7 +522,7 @@ 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; spin_unlock(&kvm_vmid_lock); -- 2.0.0