| Message ID | 20200310131223.10287-1-borntraeger@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: s390: Also reset registers in sync regs for initial cpu reset | expand |
On 10.03.20 14:12, Christian Borntraeger wrote: > When we do the initial CPU reset we must not only clear the registers > in the internal data structures but also in kvm_run sync_regs. For > modern userspace sync_regs is the only place that it looks at. > > Cc: stable@vger.kernel.org # v? > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index d7ff30e45589..c2e6d4ba4e23 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -3268,7 +3268,10 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > /* Initial reset is a superset of the normal reset */ > kvm_arch_vcpu_ioctl_normal_reset(vcpu); > > - /* this equals initial cpu reset in pop, but we don't switch to ESA */ > + /* > + * This equals initial cpu reset in pop, but we don't switch to ESA. > + * We do not only reset the internal data, but also ... > + */ > vcpu->arch.sie_block->gpsw.mask = 0; > vcpu->arch.sie_block->gpsw.addr = 0; > kvm_s390_set_prefix(vcpu, 0); > @@ -3278,6 +3281,19 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > memset(vcpu->arch.sie_block->gcr, 0, sizeof(vcpu->arch.sie_block->gcr)); > vcpu->arch.sie_block->gcr[0] = CR0_INITIAL_MASK; > vcpu->arch.sie_block->gcr[14] = CR14_INITIAL_MASK; > + > + /* ... the data in sync regs */ > + memset(vcpu->run->s.regs.crs, 0, sizeof(vcpu->run->s.regs.crs)); > + vcpu->run->s.regs.ckc = 0; > + vcpu->run->s.regs.crs[0] = CR0_INITIAL_MASK; > + vcpu->run->s.regs.crs[14] = CR14_INITIAL_MASK; > + vcpu->run->psw_addr = 0; > + vcpu->run->psw_mask = 0; > + vcpu->run->s.regs.todpr = 0; > + vcpu->run->s.regs.cputm = 0; > + vcpu->run->s.regs.ckc = 0; > + vcpu->run->s.regs.pp = 0; > + vcpu->run->s.regs.gbea = 1; > vcpu->run->s.regs.fpc = 0; > vcpu->arch.sie_block->gbea = 1; > vcpu->arch.sie_block->pp = 0; > Acked-by: David Hildenbrand <david@redhat.com> However, I do wonder if that ioctl *originally* was designed for that - IOW if this is rally a stable patch or just some change that makes sense. IIRC, userspace/QEMU always did the right thing, no? There was no documentation about the guarantees AFAIK.
On 10.03.20 14:21, David Hildenbrand wrote: > On 10.03.20 14:12, Christian Borntraeger wrote: >> When we do the initial CPU reset we must not only clear the registers >> in the internal data structures but also in kvm_run sync_regs. For >> modern userspace sync_regs is the only place that it looks at. >> >> Cc: stable@vger.kernel.org > > # v? > >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- >> 1 file changed, 17 insertions(+), 1 deletion(-) >> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index d7ff30e45589..c2e6d4ba4e23 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -3268,7 +3268,10 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >> /* Initial reset is a superset of the normal reset */ >> kvm_arch_vcpu_ioctl_normal_reset(vcpu); >> >> - /* this equals initial cpu reset in pop, but we don't switch to ESA */ >> + /* >> + * This equals initial cpu reset in pop, but we don't switch to ESA. >> + * We do not only reset the internal data, but also ... >> + */ >> vcpu->arch.sie_block->gpsw.mask = 0; >> vcpu->arch.sie_block->gpsw.addr = 0; >> kvm_s390_set_prefix(vcpu, 0); >> @@ -3278,6 +3281,19 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >> memset(vcpu->arch.sie_block->gcr, 0, sizeof(vcpu->arch.sie_block->gcr)); >> vcpu->arch.sie_block->gcr[0] = CR0_INITIAL_MASK; >> vcpu->arch.sie_block->gcr[14] = CR14_INITIAL_MASK; >> + >> + /* ... the data in sync regs */ >> + memset(vcpu->run->s.regs.crs, 0, sizeof(vcpu->run->s.regs.crs)); >> + vcpu->run->s.regs.ckc = 0; >> + vcpu->run->s.regs.crs[0] = CR0_INITIAL_MASK; >> + vcpu->run->s.regs.crs[14] = CR14_INITIAL_MASK; >> + vcpu->run->psw_addr = 0; >> + vcpu->run->psw_mask = 0; >> + vcpu->run->s.regs.todpr = 0; >> + vcpu->run->s.regs.cputm = 0; >> + vcpu->run->s.regs.ckc = 0; >> + vcpu->run->s.regs.pp = 0; >> + vcpu->run->s.regs.gbea = 1; >> vcpu->run->s.regs.fpc = 0; >> vcpu->arch.sie_block->gbea = 1; >> vcpu->arch.sie_block->pp = 0; >> > > Acked-by: David Hildenbrand <david@redhat.com> > > However, I do wonder if that ioctl *originally* was designed for that - > IOW if this is rally a stable patch or just some change that makes > sense. IIRC, userspace/QEMU always did the right thing, no? There was no > documentation about the guarantees AFAIK. > Yes, I moved forth and back. Maybe removing cc stable and just adding Fixes: 7de3f1423ff ("KVM: s390: Add new reset vcpu API") is better then.
On 10.03.20 14:23, Christian Borntraeger wrote: > > > On 10.03.20 14:21, David Hildenbrand wrote: >> On 10.03.20 14:12, Christian Borntraeger wrote: >>> When we do the initial CPU reset we must not only clear the registers >>> in the internal data structures but also in kvm_run sync_regs. For >>> modern userspace sync_regs is the only place that it looks at. >>> >>> Cc: stable@vger.kernel.org >> >> # v? >> >>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >>> --- >>> arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- >>> 1 file changed, 17 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>> index d7ff30e45589..c2e6d4ba4e23 100644 >>> --- a/arch/s390/kvm/kvm-s390.c >>> +++ b/arch/s390/kvm/kvm-s390.c >>> @@ -3268,7 +3268,10 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >>> /* Initial reset is a superset of the normal reset */ >>> kvm_arch_vcpu_ioctl_normal_reset(vcpu); >>> >>> - /* this equals initial cpu reset in pop, but we don't switch to ESA */ >>> + /* >>> + * This equals initial cpu reset in pop, but we don't switch to ESA. >>> + * We do not only reset the internal data, but also ... >>> + */ >>> vcpu->arch.sie_block->gpsw.mask = 0; >>> vcpu->arch.sie_block->gpsw.addr = 0; >>> kvm_s390_set_prefix(vcpu, 0); >>> @@ -3278,6 +3281,19 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >>> memset(vcpu->arch.sie_block->gcr, 0, sizeof(vcpu->arch.sie_block->gcr)); >>> vcpu->arch.sie_block->gcr[0] = CR0_INITIAL_MASK; >>> vcpu->arch.sie_block->gcr[14] = CR14_INITIAL_MASK; >>> + >>> + /* ... the data in sync regs */ >>> + memset(vcpu->run->s.regs.crs, 0, sizeof(vcpu->run->s.regs.crs)); >>> + vcpu->run->s.regs.ckc = 0; >>> + vcpu->run->s.regs.crs[0] = CR0_INITIAL_MASK; >>> + vcpu->run->s.regs.crs[14] = CR14_INITIAL_MASK; >>> + vcpu->run->psw_addr = 0; >>> + vcpu->run->psw_mask = 0; >>> + vcpu->run->s.regs.todpr = 0; >>> + vcpu->run->s.regs.cputm = 0; >>> + vcpu->run->s.regs.ckc = 0; >>> + vcpu->run->s.regs.pp = 0; >>> + vcpu->run->s.regs.gbea = 1; >>> vcpu->run->s.regs.fpc = 0; >>> vcpu->arch.sie_block->gbea = 1; >>> vcpu->arch.sie_block->pp = 0; >>> >> >> Acked-by: David Hildenbrand <david@redhat.com> >> >> However, I do wonder if that ioctl *originally* was designed for that - >> IOW if this is rally a stable patch or just some change that makes >> sense. IIRC, userspace/QEMU always did the right thing, no? There was no >> documentation about the guarantees AFAIK. >> > > Yes, I moved forth and back. > Maybe removing cc stable and just adding > Fixes: 7de3f1423ff ("KVM: s390: Add new reset vcpu API") > is better then. Makes sense.
On Tue, 10 Mar 2020 14:21:23 +0100 David Hildenbrand <david@redhat.com> wrote: > On 10.03.20 14:12, Christian Borntraeger wrote: > > When we do the initial CPU reset we must not only clear the registers > > in the internal data structures but also in kvm_run sync_regs. For > > modern userspace sync_regs is the only place that it looks at. > > > > Cc: stable@vger.kernel.org > > # v? > > > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > > --- > > arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- > > 1 file changed, 17 insertions(+), 1 deletion(-) > However, I do wonder if that ioctl *originally* was designed for that - > IOW if this is rally a stable patch or just some change that makes > sense. IIRC, userspace/QEMU always did the right thing, no? There was no > documentation about the guarantees AFAIK. The documentation only refers to the PoP for what is actually reset... should it also mention the sync regs?
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index d7ff30e45589..c2e6d4ba4e23 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3268,7 +3268,10 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) /* Initial reset is a superset of the normal reset */ kvm_arch_vcpu_ioctl_normal_reset(vcpu); - /* this equals initial cpu reset in pop, but we don't switch to ESA */ + /* + * This equals initial cpu reset in pop, but we don't switch to ESA. + * We do not only reset the internal data, but also ... + */ vcpu->arch.sie_block->gpsw.mask = 0; vcpu->arch.sie_block->gpsw.addr = 0; kvm_s390_set_prefix(vcpu, 0); @@ -3278,6 +3281,19 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) memset(vcpu->arch.sie_block->gcr, 0, sizeof(vcpu->arch.sie_block->gcr)); vcpu->arch.sie_block->gcr[0] = CR0_INITIAL_MASK; vcpu->arch.sie_block->gcr[14] = CR14_INITIAL_MASK; + + /* ... the data in sync regs */ + memset(vcpu->run->s.regs.crs, 0, sizeof(vcpu->run->s.regs.crs)); + vcpu->run->s.regs.ckc = 0; + vcpu->run->s.regs.crs[0] = CR0_INITIAL_MASK; + vcpu->run->s.regs.crs[14] = CR14_INITIAL_MASK; + vcpu->run->psw_addr = 0; + vcpu->run->psw_mask = 0; + vcpu->run->s.regs.todpr = 0; + vcpu->run->s.regs.cputm = 0; + vcpu->run->s.regs.ckc = 0; + vcpu->run->s.regs.pp = 0; + vcpu->run->s.regs.gbea = 1; vcpu->run->s.regs.fpc = 0; vcpu->arch.sie_block->gbea = 1; vcpu->arch.sie_block->pp = 0;
When we do the initial CPU reset we must not only clear the registers in the internal data structures but also in kvm_run sync_regs. For modern userspace sync_regs is the only place that it looks at. Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> --- arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)