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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>
hifive-unleashed-5.1
Vladimir Murzin 2018-07-31 14:08:57 +01:00 committed by Catalin Marinas
parent 5ffdfaedfa
commit ab510027dc
6 changed files with 17 additions and 2 deletions
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1
arch/arm/include/asm/kvm_arm.h
View File

@ -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)

5
arch/arm/include/asm/kvm_mmu.h
View File

@ -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__ */

1
arch/arm64/include/asm/kvm_arm.h
View File

@ -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)

5
arch/arm64/include/asm/kvm_mmu.h
View File

@ -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__ */

3
arch/arm64/kvm/hyp-init.S
View File

@ -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

4
virt/kvm/arm/arm.c
View File

@ -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);
}