From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 18 Jun 2015 18:27:18 +0100 Subject: [PATCH v2 2/2] arm: KVM: keep arm vfp/simd exit handling consistent with arm64 In-Reply-To: <1434491452-19177-3-git-send-email-m.smarduch@samsung.com> References: <1434491452-19177-1-git-send-email-m.smarduch@samsung.com> <1434491452-19177-3-git-send-email-m.smarduch@samsung.com> Message-ID: <5582FF76.6060100@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 16/06/15 22:50, Mario Smarduch wrote: > After enhancing arm64 FP/SIMD exit handling, FP/SIMD exit branch is moved > to guest trap handling. This keeps exiting handling flow between both > architectures consistent. > > Signed-off-by: Mario Smarduch > --- > arch/arm/kvm/interrupts.S | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S > index 79caf79..fca2c56 100644 > --- a/arch/arm/kvm/interrupts.S > +++ b/arch/arm/kvm/interrupts.S > @@ -363,10 +363,6 @@ hyp_hvc: > @ Check syndrome register > mrc p15, 4, r1, c5, c2, 0 @ HSR > lsr r0, r1, #HSR_EC_SHIFT > -#ifdef CONFIG_VFPv3 > - cmp r0, #HSR_EC_CP_0_13 > - beq switch_to_guest_vfp > -#endif > cmp r0, #HSR_EC_HVC > bne guest_trap @ Not HVC instr. > > @@ -406,6 +402,12 @@ THUMB( orr lr, #1) > 1: eret > > guest_trap: > +#ifdef CONFIG_VFPv3 > + /* Guest accessed VFP/SIMD registers, save host, restore Guest */ > + cmp r0, #HSR_EC_CP_0_13 > + beq switch_to_guest_fpsimd > +#endif > + > load_vcpu @ Load VCPU pointer to r0 > str r1, [vcpu, #VCPU_HSR] > > @@ -478,7 +480,7 @@ guest_trap: > * inject an undefined exception to the guest. > */ > #ifdef CONFIG_VFPv3 > -switch_to_guest_vfp: > +switch_to_guest_fpsimd: Ah, I think I managed to confuse you in my previous comment. On ARMv7, we call the floating point stuff VFP. On ARMv8, we call it FP/SIMD. Not very consistent, I know... > load_vcpu @ Load VCPU pointer to r0 It would be interesting to find out if we can make this load_vcpu part of the common sequence (without spilling another register, of course). Probably involves moving the exception class to r2. Thanks, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v2 2/2] arm: KVM: keep arm vfp/simd exit handling consistent with arm64 Date: Thu, 18 Jun 2015 18:27:18 +0100 Message-ID: <5582FF76.6060100@arm.com> References: <1434491452-19177-1-git-send-email-m.smarduch@samsung.com> <1434491452-19177-3-git-send-email-m.smarduch@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1434491452-19177-3-git-send-email-m.smarduch@samsung.com> Sender: kvm-owner@vger.kernel.org To: Mario Smarduch , "kvmarm@lists.cs.columbia.edu" , "christoffer.dall@linaro.org" Cc: "linux-arm-kernel@lists.infradead.org" , "kvm@vger.kernel.org" , Catalin Marinas , Will Deacon List-Id: kvmarm@lists.cs.columbia.edu On 16/06/15 22:50, Mario Smarduch wrote: > After enhancing arm64 FP/SIMD exit handling, FP/SIMD exit branch is moved > to guest trap handling. This keeps exiting handling flow between both > architectures consistent. > > Signed-off-by: Mario Smarduch > --- > arch/arm/kvm/interrupts.S | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S > index 79caf79..fca2c56 100644 > --- a/arch/arm/kvm/interrupts.S > +++ b/arch/arm/kvm/interrupts.S > @@ -363,10 +363,6 @@ hyp_hvc: > @ Check syndrome register > mrc p15, 4, r1, c5, c2, 0 @ HSR > lsr r0, r1, #HSR_EC_SHIFT > -#ifdef CONFIG_VFPv3 > - cmp r0, #HSR_EC_CP_0_13 > - beq switch_to_guest_vfp > -#endif > cmp r0, #HSR_EC_HVC > bne guest_trap @ Not HVC instr. > > @@ -406,6 +402,12 @@ THUMB( orr lr, #1) > 1: eret > > guest_trap: > +#ifdef CONFIG_VFPv3 > + /* Guest accessed VFP/SIMD registers, save host, restore Guest */ > + cmp r0, #HSR_EC_CP_0_13 > + beq switch_to_guest_fpsimd > +#endif > + > load_vcpu @ Load VCPU pointer to r0 > str r1, [vcpu, #VCPU_HSR] > > @@ -478,7 +480,7 @@ guest_trap: > * inject an undefined exception to the guest. > */ > #ifdef CONFIG_VFPv3 > -switch_to_guest_vfp: > +switch_to_guest_fpsimd: Ah, I think I managed to confuse you in my previous comment. On ARMv7, we call the floating point stuff VFP. On ARMv8, we call it FP/SIMD. Not very consistent, I know... > load_vcpu @ Load VCPU pointer to r0 It would be interesting to find out if we can make this load_vcpu part of the common sequence (without spilling another register, of course). Probably involves moving the exception class to r2. Thanks, M. -- Jazz is not dead. It just smells funny...