From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: [PATCH v2 09/36] KVM: arm64: Improve debug register save/restore flow Date: Thu, 7 Dec 2017 18:06:03 +0100 Message-ID: <20171207170630.592-10-christoffer.dall@linaro.org> References: <20171207170630.592-1-christoffer.dall@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 381D849D8C for ; Thu, 7 Dec 2017 12:03:41 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7JB0KR26GRpb for ; Thu, 7 Dec 2017 12:03:40 -0500 (EST) Received: from mail-wm0-f68.google.com (mail-wm0-f68.google.com [74.125.82.68]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 82AC849DAF for ; Thu, 7 Dec 2017 12:03:39 -0500 (EST) Received: by mail-wm0-f68.google.com with SMTP id b76so14240550wmg.1 for ; Thu, 07 Dec 2017 09:06:55 -0800 (PST) In-Reply-To: <20171207170630.592-1-christoffer.dall@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier , Shih-Wei Li , kvm@vger.kernel.org List-Id: kvmarm@lists.cs.columbia.edu Instead of having multiple calls from the world switch path to the debug logic, each figuring out if the dirty bit is set and if we should save/restore the debug registers, let's just provide two hooks to the debug save/restore functionality, one for switching to the guest context, and one for switching to the host context, and we get the benefit of only having to evaluate the dirty flag once on each path, plus we give the compiler some more room to inline some of this functionality. Signed-off-by: Christoffer Dall --- Notes: Changes since v1: - Remove leading underscores from local variables arch/arm64/include/asm/kvm_hyp.h | 10 ++----- arch/arm64/kvm/hyp/debug-sr.c | 56 +++++++++++++++++++++++++++------------- arch/arm64/kvm/hyp/switch.c | 6 ++--- 3 files changed, 42 insertions(+), 30 deletions(-) diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 08d3bb66c8b7..a0e5a7038237 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -139,14 +139,8 @@ void __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt); void __sysreg32_save_state(struct kvm_vcpu *vcpu); void __sysreg32_restore_state(struct kvm_vcpu *vcpu); -void __debug_save_state(struct kvm_vcpu *vcpu, - struct kvm_guest_debug_arch *dbg, - struct kvm_cpu_context *ctxt); -void __debug_restore_state(struct kvm_vcpu *vcpu, - struct kvm_guest_debug_arch *dbg, - struct kvm_cpu_context *ctxt); -void __debug_cond_save_host_state(struct kvm_vcpu *vcpu); -void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu); +void __debug_switch_to_guest(struct kvm_vcpu *vcpu); +void __debug_switch_to_host(struct kvm_vcpu *vcpu); void __fpsimd_save_state(struct user_fpsimd_state *fp_regs); void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs); diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c index 81b8ad44f9e0..ee87115eb12f 100644 --- a/arch/arm64/kvm/hyp/debug-sr.c +++ b/arch/arm64/kvm/hyp/debug-sr.c @@ -106,16 +106,13 @@ static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1) write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1); } -void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu, - struct kvm_guest_debug_arch *dbg, - struct kvm_cpu_context *ctxt) +static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu, + struct kvm_guest_debug_arch *dbg, + struct kvm_cpu_context *ctxt) { u64 aa64dfr0; int brps, wrps; - if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)) - return; - aa64dfr0 = read_sysreg(id_aa64dfr0_el1); brps = (aa64dfr0 >> 12) & 0xf; wrps = (aa64dfr0 >> 20) & 0xf; @@ -128,16 +125,13 @@ void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu, ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1); } -void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu, - struct kvm_guest_debug_arch *dbg, - struct kvm_cpu_context *ctxt) +static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu, + struct kvm_guest_debug_arch *dbg, + struct kvm_cpu_context *ctxt) { u64 aa64dfr0; int brps, wrps; - if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)) - return; - aa64dfr0 = read_sysreg(id_aa64dfr0_el1); brps = (aa64dfr0 >> 12) & 0xf; @@ -151,10 +145,12 @@ void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu, write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1); } -void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu) +void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu) { - __debug_save_state(vcpu, &vcpu->arch.host_debug_state.regs, - kern_hyp_va(vcpu->arch.host_cpu_context)); + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + struct kvm_guest_debug_arch *host_dbg; + struct kvm_guest_debug_arch *guest_dbg; /* * Non-VHE: Disable and flush SPE data generation @@ -162,15 +158,39 @@ void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu) */ if (!has_vhe()) __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1); + + if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)) + return; + + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + guest_ctxt = &vcpu->arch.ctxt; + host_dbg = &vcpu->arch.host_debug_state.regs; + guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr); + + __debug_save_state(vcpu, host_dbg, host_ctxt); + __debug_restore_state(vcpu, guest_dbg, guest_ctxt); } -void __hyp_text __debug_cond_restore_host_state(struct kvm_vcpu *vcpu) +void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu) { + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + struct kvm_guest_debug_arch *host_dbg; + struct kvm_guest_debug_arch *guest_dbg; + if (!has_vhe()) __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1); - __debug_restore_state(vcpu, &vcpu->arch.host_debug_state.regs, - kern_hyp_va(vcpu->arch.host_cpu_context)); + if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)) + return; + + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + guest_ctxt = &vcpu->arch.ctxt; + host_dbg = &vcpu->arch.host_debug_state.regs; + guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr); + + __debug_save_state(vcpu, guest_dbg, guest_ctxt); + __debug_restore_state(vcpu, host_dbg, host_ctxt); vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY; } diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index f5d53ef9ca79..6982392745f5 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -287,7 +287,6 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) guest_ctxt = &vcpu->arch.ctxt; __sysreg_save_host_state(host_ctxt); - __debug_cond_save_host_state(vcpu); __activate_traps(vcpu); __activate_vm(vcpu); @@ -301,7 +300,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) */ __sysreg32_restore_state(vcpu); __sysreg_restore_guest_state(guest_ctxt); - __debug_restore_state(vcpu, kern_hyp_va(vcpu->arch.debug_ptr), guest_ctxt); + __debug_switch_to_guest(vcpu); /* Jump in the fire! */ again: @@ -379,12 +378,11 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) __sysreg_restore_host_state(host_ctxt); - __debug_save_state(vcpu, kern_hyp_va(vcpu->arch.debug_ptr), guest_ctxt); /* * This must come after restoring the host sysregs, since a non-VHE * system may enable SPE here and make use of the TTBRs. */ - __debug_cond_restore_host_state(vcpu); + __debug_switch_to_host(vcpu); return exit_code; } -- 2.14.2