diff options
Diffstat (limited to 'arch/arm64/kvm/inject_fault.c')
| -rw-r--r-- | arch/arm64/kvm/inject_fault.c | 70 |
1 files changed, 65 insertions, 5 deletions
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index ccdb6a051ab2..6aafc2825c1c 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -14,9 +14,6 @@ #include <asm/kvm_emulate.h> #include <asm/esr.h> -#define PSTATE_FAULT_BITS_64 (PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \ - PSR_I_BIT | PSR_D_BIT) - #define CURRENT_EL_SP_EL0_VECTOR 0x0 #define CURRENT_EL_SP_ELx_VECTOR 0x200 #define LOWER_EL_AArch64_VECTOR 0x400 @@ -50,6 +47,69 @@ static u64 get_except_vector(struct kvm_vcpu *vcpu, enum exception_type type) return vcpu_read_sys_reg(vcpu, VBAR_EL1) + exc_offset + type; } +/* + * When an exception is taken, most PSTATE fields are left unchanged in the + * handler. However, some are explicitly overridden (e.g. M[4:0]). Luckily all + * of the inherited bits have the same position in the AArch64/AArch32 SPSR_ELx + * layouts, so we don't need to shuffle these for exceptions from AArch32 EL0. + * + * For the SPSR_ELx layout for AArch64, see ARM DDI 0487E.a page C5-429. + * For the SPSR_ELx layout for AArch32, see ARM DDI 0487E.a page C5-426. + * + * Here we manipulate the fields in order of the AArch64 SPSR_ELx layout, from + * MSB to LSB. + */ +static unsigned long get_except64_pstate(struct kvm_vcpu *vcpu) +{ + unsigned long sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1); + unsigned long old, new; + + old = *vcpu_cpsr(vcpu); + new = 0; + + new |= (old & PSR_N_BIT); + new |= (old & PSR_Z_BIT); + new |= (old & PSR_C_BIT); + new |= (old & PSR_V_BIT); + + // TODO: TCO (if/when ARMv8.5-MemTag is exposed to guests) + + new |= (old & PSR_DIT_BIT); + + // PSTATE.UAO is set to zero upon any exception to AArch64 + // See ARM DDI 0487E.a, page D5-2579. + + // PSTATE.PAN is unchanged unless SCTLR_ELx.SPAN == 0b0 + // SCTLR_ELx.SPAN is RES1 when ARMv8.1-PAN is not implemented + // See ARM DDI 0487E.a, page D5-2578. + new |= (old & PSR_PAN_BIT); + if (!(sctlr & SCTLR_EL1_SPAN)) + new |= PSR_PAN_BIT; + + // PSTATE.SS is set to zero upon any exception to AArch64 + // See ARM DDI 0487E.a, page D2-2452. + + // PSTATE.IL is set to zero upon any exception to AArch64 + // See ARM DDI 0487E.a, page D1-2306. + + // PSTATE.SSBS is set to SCTLR_ELx.DSSBS upon any exception to AArch64 + // See ARM DDI 0487E.a, page D13-3258 + if (sctlr & SCTLR_ELx_DSSBS) + new |= PSR_SSBS_BIT; + + // PSTATE.BTYPE is set to zero upon any exception to AArch64 + // See ARM DDI 0487E.a, pages D1-2293 to D1-2294. + + new |= PSR_D_BIT; + new |= PSR_A_BIT; + new |= PSR_I_BIT; + new |= PSR_F_BIT; + + new |= PSR_MODE_EL1h; + + return new; +} + static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr) { unsigned long cpsr = *vcpu_cpsr(vcpu); @@ -59,7 +119,7 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu)); *vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync); - *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; + *vcpu_cpsr(vcpu) = get_except64_pstate(vcpu); vcpu_write_spsr(vcpu, cpsr); vcpu_write_sys_reg(vcpu, addr, FAR_EL1); @@ -94,7 +154,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu) vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu)); *vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync); - *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; + *vcpu_cpsr(vcpu) = get_except64_pstate(vcpu); vcpu_write_spsr(vcpu, cpsr); /* |