From 717cf94adb54095d14a6674baea73123188f2901 Mon Sep 17 00:00:00 2001 From: David Brazdil Date: Tue, 22 Sep 2020 21:49:04 +0100 Subject: [PATCH] kvm: arm64: Remove __hyp_this_cpu_read this_cpu_ptr is meant for use in kernel proper because it selects between TPIDR_EL1/2 based on nVHE/VHE. __hyp_this_cpu_ptr was used in hyp to always select TPIDR_EL2. Unify all users behind this_cpu_ptr and friends by selecting _EL2 register under __KVM_NVHE_HYPERVISOR__. VHE continues selecting the register using alternatives. Under CONFIG_DEBUG_PREEMPT, the kernel helpers perform a preemption check which is omitted by the hyp helpers. Preserve the behavior for nVHE by overriding the corresponding macros under __KVM_NVHE_HYPERVISOR__. Extend the checks into VHE hyp code. Signed-off-by: David Brazdil Signed-off-by: Marc Zyngier Acked-by: Andrew Scull Acked-by: Will Deacon Link: https://lore.kernel.org/r/20200922204910.7265-5-dbrazdil@google.com --- arch/arm64/include/asm/kvm_asm.h | 20 -------------------- arch/arm64/include/asm/percpu.h | 28 ++++++++++++++++++++++++++-- arch/arm64/kvm/hyp/include/hyp/debug-sr.h | 4 ++-- arch/arm64/kvm/hyp/include/hyp/switch.h | 8 ++++---- arch/arm64/kvm/hyp/nvhe/switch.c | 2 +- arch/arm64/kvm/hyp/vhe/switch.c | 2 +- arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 4 ++-- 7 files changed, 36 insertions(+), 32 deletions(-) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index c085032e2e3e..c196eec25498 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -143,26 +143,6 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; addr; \ }) -/* - * Home-grown __this_cpu_{ptr,read} variants that always work at HYP, - * provided that sym is really a *symbol* and not a pointer obtained from - * a data structure. As for SHIFT_PERCPU_PTR(), the creative casting keeps - * sparse quiet. - */ -#define __hyp_this_cpu_ptr(sym) \ - ({ \ - void *__ptr; \ - __verify_pcpu_ptr(&sym); \ - __ptr = hyp_symbol_addr(sym); \ - __ptr += read_sysreg(tpidr_el2); \ - (typeof(sym) __kernel __force *)__ptr; \ - }) - -#define __hyp_this_cpu_read(sym) \ - ({ \ - *__hyp_this_cpu_ptr(sym); \ - }) - #define __KVM_EXTABLE(from, to) \ " .pushsection __kvm_ex_table, \"a\"\n" \ " .align 3\n" \ diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h index 0b6409b89e5e..1599e17379d8 100644 --- a/arch/arm64/include/asm/percpu.h +++ b/arch/arm64/include/asm/percpu.h @@ -19,7 +19,16 @@ static inline void set_my_cpu_offset(unsigned long off) :: "r" (off) : "memory"); } -static inline unsigned long __my_cpu_offset(void) +static inline unsigned long __hyp_my_cpu_offset(void) +{ + /* + * Non-VHE hyp code runs with preemption disabled. No need to hazard + * the register access against barrier() as in __kern_my_cpu_offset. + */ + return read_sysreg(tpidr_el2); +} + +static inline unsigned long __kern_my_cpu_offset(void) { unsigned long off; @@ -35,7 +44,12 @@ static inline unsigned long __my_cpu_offset(void) return off; } -#define __my_cpu_offset __my_cpu_offset() + +#ifdef __KVM_NVHE_HYPERVISOR__ +#define __my_cpu_offset __hyp_my_cpu_offset() +#else +#define __my_cpu_offset __kern_my_cpu_offset() +#endif #define PERCPU_RW_OPS(sz) \ static inline unsigned long __percpu_read_##sz(void *ptr) \ @@ -227,4 +241,14 @@ PERCPU_RET_OP(add, add, ldadd) #include +/* Redefine macros for nVHE hyp under DEBUG_PREEMPT to avoid its dependencies. */ +#if defined(__KVM_NVHE_HYPERVISOR__) && defined(CONFIG_DEBUG_PREEMPT) +#undef this_cpu_ptr +#define this_cpu_ptr raw_cpu_ptr +#undef __this_cpu_read +#define __this_cpu_read raw_cpu_read +#undef __this_cpu_write +#define __this_cpu_write raw_cpu_write +#endif + #endif /* __ASM_PERCPU_H */ diff --git a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h index 5e28ea6aa097..4ebe9f558f3a 100644 --- a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h @@ -135,7 +135,7 @@ static inline void __debug_switch_to_guest_common(struct kvm_vcpu *vcpu) if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) return; - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; guest_ctxt = &vcpu->arch.ctxt; host_dbg = &vcpu->arch.host_debug_state.regs; guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr); @@ -154,7 +154,7 @@ static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu) if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)) return; - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; guest_ctxt = &vcpu->arch.ctxt; host_dbg = &vcpu->arch.host_debug_state.regs; guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr); diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 5b6b8fa00f0a..f150407fa798 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -386,7 +386,7 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu) !esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu))) return false; - ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; __ptrauth_save_key(ctxt, APIA); __ptrauth_save_key(ctxt, APIB); __ptrauth_save_key(ctxt, APDA); @@ -495,7 +495,7 @@ static inline void __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu) * guest wants it disabled, so be it... */ if (__needs_ssbd_off(vcpu) && - __hyp_this_cpu_read(arm64_ssbd_callback_required)) + __this_cpu_read(arm64_ssbd_callback_required)) arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 0, NULL); #endif } @@ -507,7 +507,7 @@ static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu) * If the guest has disabled the workaround, bring it back on. */ if (__needs_ssbd_off(vcpu) && - __hyp_this_cpu_read(arm64_ssbd_callback_required)) + __this_cpu_read(arm64_ssbd_callback_required)) arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 1, NULL); #endif } @@ -521,7 +521,7 @@ static inline void __kvm_unexpected_el2_exception(void) entry = hyp_symbol_addr(__start___kvm_ex_table); end = hyp_symbol_addr(__stop___kvm_ex_table); - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; while (entry < end) { addr = (unsigned long)&entry->insn + entry->insn; diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index 0970442d2dbc..cc4f8e790fb3 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -175,7 +175,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) vcpu = kern_hyp_va(vcpu); - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; host_ctxt->__hyp_running_vcpu = vcpu; guest_ctxt = &vcpu->arch.ctxt; diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index c1da4f86ccac..575e8054f116 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -108,7 +108,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt; u64 exit_code; - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; host_ctxt->__hyp_running_vcpu = vcpu; guest_ctxt = &vcpu->arch.ctxt; diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c index 996471e4c138..2a0b8c88d74f 100644 --- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c @@ -66,7 +66,7 @@ void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; struct kvm_cpu_context *host_ctxt; - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; __sysreg_save_user_state(host_ctxt); /* @@ -100,7 +100,7 @@ void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; struct kvm_cpu_context *host_ctxt; - host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; deactivate_traps_vhe_put(); __sysreg_save_el1_state(guest_ctxt); -- 2.11.0