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authorVladimir Murzin <vladimir.murzin@arm.com>2018-07-31 14:08:57 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2018-09-18 12:03:34 +0100
commitab510027dc4dbd1eeb611a34b0cda8b21fcde492 (patch)
tree6f71d3b509e910de4db2cebd1b76f33ef11873b7
parent5ffdfaedfa0aba3f5db0fbb8ed4f3192be2b39b8 (diff)
downloadlinux-ab510027dc4dbd1eeb611a34b0cda8b21fcde492.tar.bz2
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 <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm/include/asm/kvm_arm.h1
-rw-r--r--arch/arm/include/asm/kvm_mmu.h5
-rw-r--r--arch/arm64/include/asm/kvm_arm.h1
-rw-r--r--arch/arm64/include/asm/kvm_mmu.h5
-rw-r--r--arch/arm64/kvm/hyp-init.S3
-rw-r--r--virt/kvm/arm/arm.c4
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);
}