From 6ccc971ee2c61a1ffb487e46bf6184f7df6aacfb Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 19 Apr 2024 11:29:32 +0100 Subject: KVM: arm64: nv: Add emulation for ERETAx instructions FEAT_NV has the interesting property of relying on ERET being trapped. An added complexity is that it also traps ERETAA and ERETAB, meaning that the Pointer Authentication aspect of these instruction must be emulated. Add an emulation of Pointer Authentication, limited to ERETAx (always using SP_EL2 as the modifier and ELR_EL2 as the pointer), using the Generic Authentication instructions. The emulation, however small, is placed in its own compilation unit so that it can be avoided if the configuration doesn't include it (or the toolchan in not up to the task). Reviewed-by: Joey Gouly Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20240419102935.1935571-13-maz@kernel.org Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_nested.h | 12 ++++++++++++ arch/arm64/include/asm/pgtable-hwdef.h | 1 + 2 files changed, 13 insertions(+) (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index dbc4e3a67356..5e0ab0596246 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -64,4 +64,16 @@ extern bool forward_smc_trap(struct kvm_vcpu *vcpu); int kvm_init_nv_sysregs(struct kvm *kvm); +#ifdef CONFIG_ARM64_PTR_AUTH +bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr); +#else +static inline bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr) +{ + /* We really should never execute this... */ + WARN_ON_ONCE(1); + *elr = 0xbad9acc0debadbad; + return false; +} +#endif + #endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index ef207a0d4f0d..9943ff0af4c9 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -297,6 +297,7 @@ #define TCR_TBI1 (UL(1) << 38) #define TCR_HA (UL(1) << 39) #define TCR_HD (UL(1) << 40) +#define TCR_TBID0 (UL(1) << 51) #define TCR_TBID1 (UL(1) << 52) #define TCR_NFD0 (UL(1) << 53) #define TCR_NFD1 (UL(1) << 54) -- cgit