| Message ID | 1434491452-19177-3-git-send-email-m.smarduch@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <m.smarduch@samsung.com> > --- > 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.
On 06/18/2015 10:27 AM, Marc Zyngier wrote: > 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 <m.smarduch@samsung.com> >> --- >> 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. Ah I see, I'll update. > > Not very consistent, I know... > >> load_vcpu @ Load VCPU pointer to r0 How about move it here - then it does not stick out like before. guest_trap: load_vcpu @ Load VCPU pointer to r0 str r1, [vcpu, #VCPU_HSR] @ Check if we need the fault information lsr r1, r1, #HSR_EC_SHIFT #ifdef CONFIG_VFPv3 /* Guest accessed VFP/SIMD registers, save host, restore Guest */ cmp r1, #HSR_EC_CP_0_13 beq switch_to_guest_vfp #endif Regarding "host_switch_to_hyp:" it has no reference but appears like a clean separator, that's on purpose? Thanks > > 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. >
On 19/06/15 00:49, Mario Smarduch wrote: > On 06/18/2015 10:27 AM, Marc Zyngier wrote: >> 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 <m.smarduch@samsung.com> >>> --- >>> 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. > > Ah I see, I'll update. >> >> Not very consistent, I know... >> >>> load_vcpu @ Load VCPU pointer to r0 > > How about move it here - then it does not stick out like > before. > > guest_trap: > load_vcpu @ Load VCPU pointer to r0 > str r1, [vcpu, #VCPU_HSR] > > @ Check if we need the fault information > lsr r1, r1, #HSR_EC_SHIFT > #ifdef CONFIG_VFPv3 > /* Guest accessed VFP/SIMD registers, save host, restore Guest */ > cmp r1, #HSR_EC_CP_0_13 > beq switch_to_guest_vfp > #endif That would work. > Regarding "host_switch_to_hyp:" it has no reference but appears > like a clean separator, that's on purpose? Not really. It looks like a leftover from the original HYP calling method that we used to have, before the code got merged. You could replace it by a simple comment saying that from this point on, we're dealing with a HVC call from the host. Thanks, M.
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: load_vcpu @ Load VCPU pointer to r0 push {r3-r7}
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 <m.smarduch@samsung.com> --- arch/arm/kvm/interrupts.S | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)