| Message ID | 20200224114107.4646-25-borntraeger@de.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: Add support for protected VMs | expand |
On Mon, 24 Feb 2020 06:40:55 -0500 Christian Borntraeger <borntraeger@de.ibm.com> wrote: > From: Janosch Frank <frankja@linux.ibm.com> > > For protected VMs the hypervisor can not access guest breaking event > address, program parameter, bpbc and todpr. Do not reset those fields > as the control block does not provide access to these fields. > > Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > Reviewed-by: David Hildenbrand <david@redhat.com> > [borntraeger@de.ibm.com: patch merging, splitting, fixing] > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > arch/s390/kvm/kvm-s390.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 6ab4c88f2e1d..c734e89235f9 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > kvm_s390_set_prefix(vcpu, 0); > kvm_s390_set_cpu_timer(vcpu, 0); > vcpu->arch.sie_block->ckc = 0; > - vcpu->arch.sie_block->todpr = 0; > 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; > vcpu->run->s.regs.fpc = 0; > - vcpu->arch.sie_block->gbea = 1; > - vcpu->arch.sie_block->pp = 0; > - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { > + vcpu->arch.sie_block->gbea = 1; > + vcpu->arch.sie_block->pp = 0; > + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > + vcpu->arch.sie_block->todpr = 0; What happens if we do change those values? Is it just ignored or will we get an exception on the next SIE entry? > + } > } > > static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu)
On 2/25/20 1:32 PM, Cornelia Huck wrote: > On Mon, 24 Feb 2020 06:40:55 -0500 > Christian Borntraeger <borntraeger@de.ibm.com> wrote: > >> From: Janosch Frank <frankja@linux.ibm.com> >> >> For protected VMs the hypervisor can not access guest breaking event >> address, program parameter, bpbc and todpr. Do not reset those fields >> as the control block does not provide access to these fields. >> >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> >> Reviewed-by: David Hildenbrand <david@redhat.com> >> [borntraeger@de.ibm.com: patch merging, splitting, fixing] >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> arch/s390/kvm/kvm-s390.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 6ab4c88f2e1d..c734e89235f9 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >> kvm_s390_set_prefix(vcpu, 0); >> kvm_s390_set_cpu_timer(vcpu, 0); >> vcpu->arch.sie_block->ckc = 0; >> - vcpu->arch.sie_block->todpr = 0; >> 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; >> vcpu->run->s.regs.fpc = 0; >> - vcpu->arch.sie_block->gbea = 1; >> - vcpu->arch.sie_block->pp = 0; >> - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >> + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { >> + vcpu->arch.sie_block->gbea = 1; >> + vcpu->arch.sie_block->pp = 0; >> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >> + vcpu->arch.sie_block->todpr = 0; > > What happens if we do change those values? Is it just ignored or will > we get an exception on the next SIE entry? Well, changing gbea is a bad idea because of the sida overlay. I don't think that any other is checked, but I'd need to look up the todpr changes to be completely sure. > >> + } >> } >> >> static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu) >
On Tue, 25 Feb 2020 13:51:12 +0100 Janosch Frank <frankja@linux.ibm.com> wrote: > On 2/25/20 1:32 PM, Cornelia Huck wrote: > > On Mon, 24 Feb 2020 06:40:55 -0500 > > Christian Borntraeger <borntraeger@de.ibm.com> wrote: > > > >> From: Janosch Frank <frankja@linux.ibm.com> > >> > >> For protected VMs the hypervisor can not access guest breaking event > >> address, program parameter, bpbc and todpr. Do not reset those fields > >> as the control block does not provide access to these fields. > >> > >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > >> Reviewed-by: David Hildenbrand <david@redhat.com> > >> [borntraeger@de.ibm.com: patch merging, splitting, fixing] > >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > >> --- > >> arch/s390/kvm/kvm-s390.c | 10 ++++++---- > >> 1 file changed, 6 insertions(+), 4 deletions(-) > >> > >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > >> index 6ab4c88f2e1d..c734e89235f9 100644 > >> --- a/arch/s390/kvm/kvm-s390.c > >> +++ b/arch/s390/kvm/kvm-s390.c > >> @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > >> kvm_s390_set_prefix(vcpu, 0); > >> kvm_s390_set_cpu_timer(vcpu, 0); > >> vcpu->arch.sie_block->ckc = 0; > >> - vcpu->arch.sie_block->todpr = 0; > >> 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; > >> vcpu->run->s.regs.fpc = 0; > >> - vcpu->arch.sie_block->gbea = 1; > >> - vcpu->arch.sie_block->pp = 0; > >> - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > >> + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { > >> + vcpu->arch.sie_block->gbea = 1; > >> + vcpu->arch.sie_block->pp = 0; > >> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > >> + vcpu->arch.sie_block->todpr = 0; > > > > What happens if we do change those values? Is it just ignored or will > > we get an exception on the next SIE entry? > > Well, changing gbea is a bad idea because of the sida overlay. > I don't think that any other is checked, but I'd need to look up the > todpr changes to be completely sure. Maybe add a comment /* * Do not reset these registers in the protected case, as some of * them are overlayed and they are not accessible in this case * anyway. */ ? Just to avoid headscratching once this dropped out of our caches. > > > > >> + } > >> } > >> > >> static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu) > > > >
On 25.02.20 13:32, Cornelia Huck wrote: > On Mon, 24 Feb 2020 06:40:55 -0500 > Christian Borntraeger <borntraeger@de.ibm.com> wrote: > >> From: Janosch Frank <frankja@linux.ibm.com> >> >> For protected VMs the hypervisor can not access guest breaking event >> address, program parameter, bpbc and todpr. Do not reset those fields >> as the control block does not provide access to these fields. >> >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> >> Reviewed-by: David Hildenbrand <david@redhat.com> >> [borntraeger@de.ibm.com: patch merging, splitting, fixing] >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> arch/s390/kvm/kvm-s390.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 6ab4c88f2e1d..c734e89235f9 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >> kvm_s390_set_prefix(vcpu, 0); >> kvm_s390_set_cpu_timer(vcpu, 0); >> vcpu->arch.sie_block->ckc = 0; >> - vcpu->arch.sie_block->todpr = 0; >> 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; >> vcpu->run->s.regs.fpc = 0; >> - vcpu->arch.sie_block->gbea = 1; >> - vcpu->arch.sie_block->pp = 0; >> - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >> + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { >> + vcpu->arch.sie_block->gbea = 1; >> + vcpu->arch.sie_block->pp = 0; >> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >> + vcpu->arch.sie_block->todpr = 0; > > What happens if we do change those values? Is it just ignored or will > we get an exception on the next SIE entry? These fields (offsets in the sie control block) are not defined or re-defined for secure guests. So we better leave them unchanged.
On 25.02.20 14:06, Cornelia Huck wrote: > On Tue, 25 Feb 2020 13:51:12 +0100 > Janosch Frank <frankja@linux.ibm.com> wrote: > >> On 2/25/20 1:32 PM, Cornelia Huck wrote: >>> On Mon, 24 Feb 2020 06:40:55 -0500 >>> Christian Borntraeger <borntraeger@de.ibm.com> wrote: >>> >>>> From: Janosch Frank <frankja@linux.ibm.com> >>>> >>>> For protected VMs the hypervisor can not access guest breaking event >>>> address, program parameter, bpbc and todpr. Do not reset those fields >>>> as the control block does not provide access to these fields. >>>> >>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> >>>> Reviewed-by: David Hildenbrand <david@redhat.com> >>>> [borntraeger@de.ibm.com: patch merging, splitting, fixing] >>>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >>>> --- >>>> arch/s390/kvm/kvm-s390.c | 10 ++++++---- >>>> 1 file changed, 6 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>>> index 6ab4c88f2e1d..c734e89235f9 100644 >>>> --- a/arch/s390/kvm/kvm-s390.c >>>> +++ b/arch/s390/kvm/kvm-s390.c >>>> @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >>>> kvm_s390_set_prefix(vcpu, 0); >>>> kvm_s390_set_cpu_timer(vcpu, 0); >>>> vcpu->arch.sie_block->ckc = 0; >>>> - vcpu->arch.sie_block->todpr = 0; >>>> 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; >>>> vcpu->run->s.regs.fpc = 0; >>>> - vcpu->arch.sie_block->gbea = 1; >>>> - vcpu->arch.sie_block->pp = 0; >>>> - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >>>> + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { >>>> + vcpu->arch.sie_block->gbea = 1; >>>> + vcpu->arch.sie_block->pp = 0; >>>> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >>>> + vcpu->arch.sie_block->todpr = 0; >>> >>> What happens if we do change those values? Is it just ignored or will >>> we get an exception on the next SIE entry? >> >> Well, changing gbea is a bad idea because of the sida overlay. >> I don't think that any other is checked, but I'd need to look up the >> todpr changes to be completely sure. > > Maybe add a comment > > /* > * Do not reset these registers in the protected case, as some of > * them are overlayed and they are not accessible in this case > * anyway. > */ Makes sense, will add.
On Tue, 25 Feb 2020 14:08:16 +0100 Christian Borntraeger <borntraeger@de.ibm.com> wrote: > On 25.02.20 14:06, Cornelia Huck wrote: > > On Tue, 25 Feb 2020 13:51:12 +0100 > > Janosch Frank <frankja@linux.ibm.com> wrote: > > > >> On 2/25/20 1:32 PM, Cornelia Huck wrote: > >>> On Mon, 24 Feb 2020 06:40:55 -0500 > >>> Christian Borntraeger <borntraeger@de.ibm.com> wrote: > >>> > >>>> From: Janosch Frank <frankja@linux.ibm.com> > >>>> > >>>> For protected VMs the hypervisor can not access guest breaking event > >>>> address, program parameter, bpbc and todpr. Do not reset those fields > >>>> as the control block does not provide access to these fields. > >>>> > >>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> > >>>> Reviewed-by: David Hildenbrand <david@redhat.com> > >>>> [borntraeger@de.ibm.com: patch merging, splitting, fixing] > >>>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > >>>> --- > >>>> arch/s390/kvm/kvm-s390.c | 10 ++++++---- > >>>> 1 file changed, 6 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > >>>> index 6ab4c88f2e1d..c734e89235f9 100644 > >>>> --- a/arch/s390/kvm/kvm-s390.c > >>>> +++ b/arch/s390/kvm/kvm-s390.c > >>>> @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) > >>>> kvm_s390_set_prefix(vcpu, 0); > >>>> kvm_s390_set_cpu_timer(vcpu, 0); > >>>> vcpu->arch.sie_block->ckc = 0; > >>>> - vcpu->arch.sie_block->todpr = 0; > >>>> 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; > >>>> vcpu->run->s.regs.fpc = 0; > >>>> - vcpu->arch.sie_block->gbea = 1; > >>>> - vcpu->arch.sie_block->pp = 0; > >>>> - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > >>>> + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { > >>>> + vcpu->arch.sie_block->gbea = 1; > >>>> + vcpu->arch.sie_block->pp = 0; > >>>> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; > >>>> + vcpu->arch.sie_block->todpr = 0; > >>> > >>> What happens if we do change those values? Is it just ignored or will > >>> we get an exception on the next SIE entry? > >> > >> Well, changing gbea is a bad idea because of the sida overlay. > >> I don't think that any other is checked, but I'd need to look up the > >> todpr changes to be completely sure. > > > > Maybe add a comment > > > > /* > > * Do not reset these registers in the protected case, as some of > > * them are overlayed and they are not accessible in this case > > * anyway. > > */ > > Makes sense, will add. > With that: Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 6ab4c88f2e1d..c734e89235f9 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3499,14 +3499,16 @@ static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) kvm_s390_set_prefix(vcpu, 0); kvm_s390_set_cpu_timer(vcpu, 0); vcpu->arch.sie_block->ckc = 0; - vcpu->arch.sie_block->todpr = 0; 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; vcpu->run->s.regs.fpc = 0; - vcpu->arch.sie_block->gbea = 1; - vcpu->arch.sie_block->pp = 0; - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; + if (!kvm_s390_pv_cpu_is_protected(vcpu)) { + vcpu->arch.sie_block->gbea = 1; + vcpu->arch.sie_block->pp = 0; + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; + vcpu->arch.sie_block->todpr = 0; + } } static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu)