diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/kvm_arm.h | 5 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp.S | 73 |
2 files changed, 68 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index ac6fafb95fe7..7605e095217f 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -171,10 +171,13 @@ #define HSTR_EL2_TTEE (1 << 16) #define HSTR_EL2_T(x) (1 << x) +/* Hyp Coproccessor Trap Register Shifts */ +#define CPTR_EL2_TFP_SHIFT 10 + /* Hyp Coprocessor Trap Register */ #define CPTR_EL2_TCPAC (1 << 31) #define CPTR_EL2_TTA (1 << 20) -#define CPTR_EL2_TFP (1 << 10) +#define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT) /* Hyp Debug Configuration Register bits */ #define MDCR_EL2_TDRA (1 << 11) diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index d93c0a23630e..8188f6ae8fc4 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -385,6 +385,14 @@ tbz \tmp, #KVM_ARM64_DEBUG_DIRTY_SHIFT, \target .endm +/* + * Branch to target if CPTR_EL2.TFP bit is set (VFP/SIMD trapping enabled) + */ +.macro skip_fpsimd_state tmp, target + mrs \tmp, cptr_el2 + tbnz \tmp, #CPTR_EL2_TFP_SHIFT, \target +.endm + .macro compute_debug_state target // Compute debug state: If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY // is set, we do a full save/restore cycle and disable trapping. @@ -423,10 +431,12 @@ add x3, x2, #CPU_SYSREG_OFFSET(DACR32_EL2) mrs x4, dacr32_el2 mrs x5, ifsr32_el2 - mrs x6, fpexc32_el2 stp x4, x5, [x3] - str x6, [x3, #16] + skip_fpsimd_state x8, 3f + mrs x6, fpexc32_el2 + str x6, [x3, #16] +3: skip_debug_state x8, 2f mrs x7, dbgvcr32_el2 str x7, [x3, #24] @@ -453,10 +463,8 @@ add x3, x2, #CPU_SYSREG_OFFSET(DACR32_EL2) ldp x4, x5, [x3] - ldr x6, [x3, #16] msr dacr32_el2, x4 msr ifsr32_el2, x5 - msr fpexc32_el2, x6 skip_debug_state x8, 2f ldr x7, [x3, #24] @@ -473,8 +481,22 @@ .macro activate_traps ldr x2, [x0, #VCPU_HCR_EL2] + + /* + * We are about to set CPTR_EL2.TFP to trap all floating point + * register accesses to EL2, however, the ARM ARM clearly states that + * traps are only taken to EL2 if the operation would not otherwise + * trap to EL1. Therefore, always make sure that for 32-bit guests, + * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. + */ + tbnz x2, #HCR_RW_SHIFT, 99f // open code skip_32bit_state + mov x3, #(1 << 30) + msr fpexc32_el2, x3 + isb +99: msr hcr_el2, x2 mov x2, #CPTR_EL2_TTA + orr x2, x2, #CPTR_EL2_TFP msr cptr_el2, x2 mov x2, #(1 << 15) // Trap CP15 Cr=15 @@ -488,7 +510,6 @@ .macro deactivate_traps mov x2, #HCR_RW msr hcr_el2, x2 - msr cptr_el2, xzr msr hstr_el2, xzr mrs x2, mdcr_el2 @@ -653,12 +674,41 @@ __restore_debug: ret __save_fpsimd: + skip_fpsimd_state x3, 1f save_fpsimd - ret +1: ret __restore_fpsimd: + skip_fpsimd_state x3, 1f restore_fpsimd - ret +1: ret + +switch_to_guest_fpsimd: + push x4, lr + + mrs x2, cptr_el2 + bic x2, x2, #CPTR_EL2_TFP + msr cptr_el2, x2 + isb + + mrs x0, tpidr_el2 + + ldr x2, [x0, #VCPU_HOST_CONTEXT] + kern_hyp_va x2 + bl __save_fpsimd + + add x2, x0, #VCPU_CONTEXT + bl __restore_fpsimd + + skip_32bit_state x3, 1f + ldr x4, [x2, #CPU_SYSREG_OFFSET(FPEXC32_EL2)] + msr fpexc32_el2, x4 +1: + pop x4, lr + pop x2, x3 + pop x0, x1 + + eret /* * u64 __kvm_vcpu_run(struct kvm_vcpu *vcpu); @@ -680,7 +730,6 @@ ENTRY(__kvm_vcpu_run) kern_hyp_va x2 save_host_regs - bl __save_fpsimd bl __save_sysregs compute_debug_state 1f @@ -697,7 +746,6 @@ ENTRY(__kvm_vcpu_run) add x2, x0, #VCPU_CONTEXT bl __restore_sysregs - bl __restore_fpsimd skip_debug_state x3, 1f ldr x3, [x0, #VCPU_DEBUG_PTR] @@ -740,6 +788,8 @@ __kvm_vcpu_return: bl __restore_sysregs bl __restore_fpsimd + /* Clear FPSIMD and Trace trapping */ + msr cptr_el2, xzr skip_debug_state x3, 1f // Clear the dirty flag for the next run, as all the state has @@ -949,6 +999,11 @@ el1_trap: * x1: ESR * x2: ESR_EC */ + + /* Guest accessed VFP/SIMD registers, save host, restore Guest */ + cmp x2, #ESR_ELx_EC_FP_ASIMD + b.eq switch_to_guest_fpsimd + cmp x2, #ESR_ELx_EC_DABT_LOW mov x0, #ESR_ELx_EC_IABT_LOW ccmp x2, x0, #4, ne |