| Message ID | 1533739472-7172-22-git-send-email-akrowiak@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio-ap: guest dedicated crypto adapters | expand |
On 08.08.2018 16:44, Tony Krowiak wrote: > From: Tony Krowiak <akrowiak@linux.ibm.com> > > Introduces a new CPU model feature and two CPU model > facilities to support AP virtualization for KVM guests. > > CPU model feature: > > The KVM_S390_VM_CPU_FEAT_AP feature indicates that > AP instructions are available on the guest. This > feature will be enabled by the kernel only if the AP > instructions are installed on the linux host. This feature > must be specifically turned on for the KVM guest from > userspace to use the VFIO AP device driver for guest > access to AP devices. > > CPU model facilities: > > 1. AP Query Configuration Information (QCI) facility is installed. > > This is indicated by setting facilities bit 12 for > the guest. The kernel will not enable this facility > for the guest if it is not set on the host. This facility > must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP > feature is not installed. Could it happen on real HW (not frankenstein CPU models), that !AP, but STFL 12 or 15 are indicated? > > If this facility is not set for the KVM guest, then only > APQNs with an APQI less than 16 will be used by a Linux > guest regardless of the matrix configuration for the virtual > machine. This is a limitation of the Linux AP bus. > > 2. AP Facilities Test facility (APFT) is installed. > > This is indicated by setting facilities bit 15 for > the guest. The kernel will not enable this facility for > the guest if it is not set on the host. This facility > must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP > feature is not installed. > > If this facility is not set for the KVM guest, then no > AP devices will be available to the guest regardless of > the guest's matrix configuration for the virtual > machine. This is a limitation of the Linux AP bus. > > Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> > Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> > Reviewed-by: Halil Pasic <pasic@linux.ibm.com> > Tested-by: Michael Mueller <mimu@linux.ibm.com> > Tested-by: Farhan Ali <alifm@linux.ibm.com> > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > arch/s390/kvm/kvm-s390.c | 7 +++++++ > arch/s390/tools/gen_facilities.c | 2 ++ > 2 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 9203f0b..7d4fe9b 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -367,6 +367,13 @@ static void kvm_s390_cpu_feat_init(void) > > if (MACHINE_HAS_ESOP) > allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); > + > + /* > + * Check if AP instructions installed on host > + */ Make this a one-line comment, please. > + if (ap_instructions_available() == 0) > + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); > + > /* > * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), > * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). > diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c > index 90a8c9e..a52290b 100644 > --- a/arch/s390/tools/gen_facilities.c > +++ b/arch/s390/tools/gen_facilities.c > @@ -106,6 +106,8 @@ struct facility_def { > > .name = "FACILITIES_KVM_CPUMODEL", > .bits = (int[]){ > + 12, /* AP Query Configuration Information */ > + 15, /* AP Facilities Test */ > -1 /* END */ > } > }, >
On 09.08.2018 10:17, David Hildenbrand wrote: > On 08.08.2018 16:44, Tony Krowiak wrote: >> From: Tony Krowiak <akrowiak@linux.ibm.com> >> >> Introduces a new CPU model feature and two CPU model >> facilities to support AP virtualization for KVM guests. >> >> CPU model feature: >> >> The KVM_S390_VM_CPU_FEAT_AP feature indicates that >> AP instructions are available on the guest. This >> feature will be enabled by the kernel only if the AP >> instructions are installed on the linux host. This feature >> must be specifically turned on for the KVM guest from >> userspace to use the VFIO AP device driver for guest >> access to AP devices. >> >> CPU model facilities: >> >> 1. AP Query Configuration Information (QCI) facility is installed. >> >> This is indicated by setting facilities bit 12 for >> the guest. The kernel will not enable this facility >> for the guest if it is not set on the host. This facility >> must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP >> feature is not installed. > Could it happen on real HW (not frankenstein CPU models), that > > !AP, but STFL 12 or 15 are indicated? What is your expectation here ? There are no AP instructions available but if there would be AP instructions available then there would be the QCI and or the T bit facility within the PQAP AP instruction valid ? >> If this facility is not set for the KVM guest, then only >> APQNs with an APQI less than 16 will be used by a Linux >> guest regardless of the matrix configuration for the virtual >> machine. This is a limitation of the Linux AP bus. >> >> 2. AP Facilities Test facility (APFT) is installed. >> >> This is indicated by setting facilities bit 15 for >> the guest. The kernel will not enable this facility for >> the guest if it is not set on the host. This facility >> must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP >> feature is not installed. >> >> If this facility is not set for the KVM guest, then no >> AP devices will be available to the guest regardless of >> the guest's matrix configuration for the virtual >> machine. This is a limitation of the Linux AP bus. >> >> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> >> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> >> Tested-by: Michael Mueller <mimu@linux.ibm.com> >> Tested-by: Farhan Ali <alifm@linux.ibm.com> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> arch/s390/kvm/kvm-s390.c | 7 +++++++ >> arch/s390/tools/gen_facilities.c | 2 ++ >> 2 files changed, 9 insertions(+), 0 deletions(-) >> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 9203f0b..7d4fe9b 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -367,6 +367,13 @@ static void kvm_s390_cpu_feat_init(void) >> >> if (MACHINE_HAS_ESOP) >> allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); >> + >> + /* >> + * Check if AP instructions installed on host >> + */ > Make this a one-line comment, please. > >> + if (ap_instructions_available() == 0) >> + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); >> + >> /* >> * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), >> * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). >> diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c >> index 90a8c9e..a52290b 100644 >> --- a/arch/s390/tools/gen_facilities.c >> +++ b/arch/s390/tools/gen_facilities.c >> @@ -106,6 +106,8 @@ struct facility_def { >> >> .name = "FACILITIES_KVM_CPUMODEL", >> .bits = (int[]){ >> + 12, /* AP Query Configuration Information */ >> + 15, /* AP Facilities Test */ >> -1 /* END */ >> } >> }, >> >
On 08/09/2018 04:17 AM, David Hildenbrand wrote: > On 08.08.2018 16:44, Tony Krowiak wrote: >> From: Tony Krowiak <akrowiak@linux.ibm.com> >> >> Introduces a new CPU model feature and two CPU model >> facilities to support AP virtualization for KVM guests. >> >> CPU model feature: >> >> The KVM_S390_VM_CPU_FEAT_AP feature indicates that >> AP instructions are available on the guest. This >> feature will be enabled by the kernel only if the AP >> instructions are installed on the linux host. This feature >> must be specifically turned on for the KVM guest from >> userspace to use the VFIO AP device driver for guest >> access to AP devices. >> >> CPU model facilities: >> >> 1. AP Query Configuration Information (QCI) facility is installed. >> >> This is indicated by setting facilities bit 12 for >> the guest. The kernel will not enable this facility >> for the guest if it is not set on the host. This facility >> must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP >> feature is not installed. > Could it happen on real HW (not frankenstein CPU models), that > > !AP, but STFL 12 or 15 are indicated? I suspect that if AP instructions are not installed, then neither STFLE.12 nor STFLE.15 would be set in the real hardware. This comment, however, is talking about an administrator setting the facility for a guest, not real hardware. Having said that and after thinking about it a little more, I am going to remove that last sentence because the CPU model configuration (e.g., as specified on the qemu command line) will fail if the QCI or APFT facility is enabled when the CPU model feature KVM_S390_VM_CPU_FEAT_AP is not. > >> If this facility is not set for the KVM guest, then only >> APQNs with an APQI less than 16 will be used by a Linux >> guest regardless of the matrix configuration for the virtual >> machine. This is a limitation of the Linux AP bus. >> >> 2. AP Facilities Test facility (APFT) is installed. >> >> This is indicated by setting facilities bit 15 for >> the guest. The kernel will not enable this facility for >> the guest if it is not set on the host. This facility >> must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP >> feature is not installed. >> >> If this facility is not set for the KVM guest, then no >> AP devices will be available to the guest regardless of >> the guest's matrix configuration for the virtual >> machine. This is a limitation of the Linux AP bus. >> >> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> >> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> >> Tested-by: Michael Mueller <mimu@linux.ibm.com> >> Tested-by: Farhan Ali <alifm@linux.ibm.com> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> arch/s390/kvm/kvm-s390.c | 7 +++++++ >> arch/s390/tools/gen_facilities.c | 2 ++ >> 2 files changed, 9 insertions(+), 0 deletions(-) >> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 9203f0b..7d4fe9b 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -367,6 +367,13 @@ static void kvm_s390_cpu_feat_init(void) >> >> if (MACHINE_HAS_ESOP) >> allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); >> + >> + /* >> + * Check if AP instructions installed on host >> + */ > Make this a one-line comment, please. Will do > >> + if (ap_instructions_available() == 0) >> + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); >> + >> /* >> * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), >> * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). >> diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c >> index 90a8c9e..a52290b 100644 >> --- a/arch/s390/tools/gen_facilities.c >> +++ b/arch/s390/tools/gen_facilities.c >> @@ -106,6 +106,8 @@ struct facility_def { >> >> .name = "FACILITIES_KVM_CPUMODEL", >> .bits = (int[]){ >> + 12, /* AP Query Configuration Information */ >> + 15, /* AP Facilities Test */ >> -1 /* END */ >> } >> }, >> >
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 9203f0b..7d4fe9b 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -367,6 +367,13 @@ static void kvm_s390_cpu_feat_init(void) if (MACHINE_HAS_ESOP) allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); + + /* + * Check if AP instructions installed on host + */ + if (ap_instructions_available() == 0) + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); + /* * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c index 90a8c9e..a52290b 100644 --- a/arch/s390/tools/gen_facilities.c +++ b/arch/s390/tools/gen_facilities.c @@ -106,6 +106,8 @@ struct facility_def { .name = "FACILITIES_KVM_CPUMODEL", .bits = (int[]){ + 12, /* AP Query Configuration Information */ + 15, /* AP Facilities Test */ -1 /* END */ } },