diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/sysreg-sr.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/sysreg-sr.c | 172 |
1 files changed, 138 insertions, 34 deletions
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 2c17afd2be96..b3894df6bf1a 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -19,32 +19,43 @@ #include <linux/kvm_host.h> #include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> #include <asm/kvm_hyp.h> -/* Yes, this does nothing, on purpose */ -static void __hyp_text __sysreg_do_nothing(struct kvm_cpu_context *ctxt) { } - /* * Non-VHE: Both host and guest must save everything. * - * VHE: Host must save tpidr*_el0, actlr_el1, mdscr_el1, sp_el0, - * and guest must save everything. + * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and pstate, + * which are handled as part of the el2 return state) on every switch. + * tpidr_el0 and tpidrro_el0 only need to be switched when going + * to host userspace or a different VCPU. EL1 registers only need to be + * switched when potentially going to run a different VCPU. The latter two + * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put. */ static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt) { - ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); - ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0); - ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0); ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1); + + /* + * The host arm64 Linux uses sp_el0 to point to 'current' and it must + * therefore be saved/restored on every entry/exit to/from the guest. + */ ctxt->gp_regs.regs.sp = read_sysreg(sp_el0); } -static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) +static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt) +{ + ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0); + ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0); +} + +static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) { ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2); ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1); ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr); + ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr); ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0); ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1); @@ -64,6 +75,10 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1); ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr); ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr); +} + +static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt) +{ ctxt->gp_regs.regs.pc = read_sysreg_el2(elr); ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr); @@ -71,36 +86,48 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2); } -static hyp_alternate_select(__sysreg_call_save_host_state, - __sysreg_save_state, __sysreg_do_nothing, - ARM64_HAS_VIRT_HOST_EXTN); +void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_save_el1_state(ctxt); + __sysreg_save_common_state(ctxt); + __sysreg_save_user_state(ctxt); + __sysreg_save_el2_return_state(ctxt); +} -void __hyp_text __sysreg_save_host_state(struct kvm_cpu_context *ctxt) +void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt) { - __sysreg_call_save_host_state()(ctxt); __sysreg_save_common_state(ctxt); } -void __hyp_text __sysreg_save_guest_state(struct kvm_cpu_context *ctxt) +void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt) { - __sysreg_save_state(ctxt); __sysreg_save_common_state(ctxt); + __sysreg_save_el2_return_state(ctxt); } static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt) { - write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1); - write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0); - write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0); write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1); + + /* + * The host arm64 Linux uses sp_el0 to point to 'current' and it must + * therefore be saved/restored on every entry/exit to/from the guest. + */ write_sysreg(ctxt->gp_regs.regs.sp, sp_el0); } -static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt) +static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt) +{ + write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0); + write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0); +} + +static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) { write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2); write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1); write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr); + write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1); write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr); write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], ttbr0); write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], ttbr1); @@ -120,6 +147,11 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt) write_sysreg(ctxt->gp_regs.sp_el1, sp_el1); write_sysreg_el1(ctxt->gp_regs.elr_el1, elr); write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr); +} + +static void __hyp_text +__sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt) +{ write_sysreg_el2(ctxt->gp_regs.regs.pc, elr); write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr); @@ -127,27 +159,30 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt) write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2); } -static hyp_alternate_select(__sysreg_call_restore_host_state, - __sysreg_restore_state, __sysreg_do_nothing, - ARM64_HAS_VIRT_HOST_EXTN); +void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_restore_el1_state(ctxt); + __sysreg_restore_common_state(ctxt); + __sysreg_restore_user_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); +} -void __hyp_text __sysreg_restore_host_state(struct kvm_cpu_context *ctxt) +void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt) { - __sysreg_call_restore_host_state()(ctxt); __sysreg_restore_common_state(ctxt); } -void __hyp_text __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt) +void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt) { - __sysreg_restore_state(ctxt); __sysreg_restore_common_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); } void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu) { u64 *spsr, *sysreg; - if (read_sysreg(hcr_el2) & HCR_RW) + if (!vcpu_el1_is_32bit(vcpu)) return; spsr = vcpu->arch.ctxt.gp_regs.spsr; @@ -161,10 +196,7 @@ void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu) sysreg[DACR32_EL2] = read_sysreg(dacr32_el2); sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2); - if (__fpsimd_enabled()) - sysreg[FPEXC32_EL2] = read_sysreg(fpexc32_el2); - - if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) + if (has_vhe() || vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2); } @@ -172,7 +204,7 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu) { u64 *spsr, *sysreg; - if (read_sysreg(hcr_el2) & HCR_RW) + if (!vcpu_el1_is_32bit(vcpu)) return; spsr = vcpu->arch.ctxt.gp_regs.spsr; @@ -186,6 +218,78 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu) write_sysreg(sysreg[DACR32_EL2], dacr32_el2); write_sysreg(sysreg[IFSR32_EL2], ifsr32_el2); - if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) + if (has_vhe() || vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2); } + +/** + * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Load system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_load() function + * and loading system register state early avoids having to load them on + * every entry to the VM. + */ +void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context; + struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; + + if (!has_vhe()) + return; + + __sysreg_save_user_state(host_ctxt); + + /* + * Load guest EL1 and user state + * + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_user_state(guest_ctxt); + __sysreg_restore_el1_state(guest_ctxt); + + vcpu->arch.sysregs_loaded_on_cpu = true; + + activate_traps_vhe_load(vcpu); +} + +/** + * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU + * + * @vcpu: The VCPU pointer + * + * Save guest system registers that do not affect the host's execution, for + * example EL1 system registers on a VHE system where the host kernel + * runs at EL2. This function is called from KVM's vcpu_put() function + * and deferring saving system register state until we're no longer running the + * VCPU avoids having to save them on every exit from the VM. + */ +void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context; + struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; + + if (!has_vhe()) + return; + + deactivate_traps_vhe_put(); + + __sysreg_save_el1_state(guest_ctxt); + __sysreg_save_user_state(guest_ctxt); + __sysreg32_save_state(vcpu); + + /* Restore host user state */ + __sysreg_restore_user_state(host_ctxt); + + vcpu->arch.sysregs_loaded_on_cpu = false; +} + +void __hyp_text __kvm_set_tpidr_el2(u64 tpidr_el2) +{ + asm("msr tpidr_el2, %0": : "r" (tpidr_el2)); +} |