| Message ID | 1526638022-4137-3-git-send-email-vladimir.murzin@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, May 18, 2018 at 11:07:01AM +0100, Vladimir Murzin wrote: > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index a4c1b76..9a651a2 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -472,7 +472,7 @@ 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; Please define a VTTBR_CNP_BIT here instead of a hard-coded value. > bool new_gen; > > read_lock(&kvm_vmid_lock); > @@ -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; > > write_unlock(&kvm_vmid_lock); > }
Hi Vladimir, On 18/05/18 11:07, Vladimir Murzin wrote: > 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. With the bare-constant fix suggested by Catalin, Reviewed-by: James Morse <james.morse@arm.com> Thanks, James
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 707a1f0..9c83710 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -321,6 +321,11 @@ 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 0821109..c9ee6c3 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -459,5 +459,10 @@ 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 6fd91b3..94998d5 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 a4c1b76..9a651a2 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -472,7 +472,7 @@ 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; bool new_gen; read_lock(&kvm_vmid_lock); @@ -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; write_unlock(&kvm_vmid_lock); }
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 <vladimir.murzin@arm.com> --- 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(-)