Re: [PATCH 14/32] KVM: s390: pci: do initial setup for AEN interpretation

[Pierre Morel]

On 12/10/21 10:54, Pierre Morel wrote:
> On 12/7/21 21:57, Matthew Rosato wrote:
> > Initial setup for Adapter Event Notification Interpretation for zPCI
> > passthrough devices.  Specifically, allocate a structure for 
> > forwarding of
> > adapter events and pass the address of this structure to firmware.
> >
> > Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> > ---
> >   arch/s390/include/asm/pci_insn.h |  12 ++++
> >   arch/s390/kvm/interrupt.c        |  17 +++++
> >   arch/s390/kvm/kvm-s390.c         |   3 +
> >   arch/s390/kvm/pci.c              | 113 +++++++++++++++++++++++++++++++
> >   arch/s390/kvm/pci.h              |  42 ++++++++++++
> >   5 files changed, 187 insertions(+)
> >   create mode 100644 arch/s390/kvm/pci.h
> >
> > diff --git a/arch/s390/include/asm/pci_insn.h 
> > b/arch/s390/include/asm/pci_insn.h
> > index 5331082fa516..e5f57cfe1d45 100644
> > --- a/arch/s390/include/asm/pci_insn.h
> > +++ b/arch/s390/include/asm/pci_insn.h
> > @@ -101,6 +101,7 @@ struct zpci_fib {
> >   /* Set Interruption Controls Operation Controls  */
> >   #define    SIC_IRQ_MODE_ALL        0
> >   #define    SIC_IRQ_MODE_SINGLE        1
> > +#define    SIC_SET_AENI_CONTROLS        2
> >   #define    SIC_IRQ_MODE_DIRECT        4
> >   #define    SIC_IRQ_MODE_D_ALL        16
> >   #define    SIC_IRQ_MODE_D_SINGLE        17
> > @@ -127,9 +128,20 @@ struct zpci_cdiib {
> >       u64 : 64;
> >   } __packed __aligned(8);
> > +/* adapter interruption parameters block */
> > +struct zpci_aipb {
> > +    u64 faisb;
> > +    u64 gait;
> > +    u16 : 13;
> > +    u16 afi : 3;
> > +    u32 : 32;
> > +    u16 faal;
> > +} __packed __aligned(8);
> > +
> >   union zpci_sic_iib {
> >       struct zpci_diib diib;
> >       struct zpci_cdiib cdiib;
> > +    struct zpci_aipb aipb;
> >   };
> >   DECLARE_STATIC_KEY_FALSE(have_mio);
> > diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> > index f9b872e358c6..4efe0e95a40f 100644
> > --- a/arch/s390/kvm/interrupt.c
> > +++ b/arch/s390/kvm/interrupt.c
> > @@ -32,6 +32,7 @@
> >   #include "kvm-s390.h"
> >   #include "gaccess.h"
> >   #include "trace-s390.h"
> > +#include "pci.h"
> >   #define PFAULT_INIT 0x0600
> >   #define PFAULT_DONE 0x0680
> > @@ -3276,8 +3277,16 @@ static struct airq_struct gib_alert_irq = {
> >   void kvm_s390_gib_destroy(void)
> >   {
> > +    struct zpci_aift *aift;
> > +
> >       if (!gib)
> >           return;
> > +    aift = kvm_s390_pci_get_aift();
> > +    if (aift) {
> > +        mutex_lock(&aift->lock);
> > +        kvm_s390_pci_aen_exit();
>
> Shouldn't we check for CONFIG_PCI and sclp.gas_aeni here as in gib_init ?
>
> > +        mutex_unlock(&aift->lock);
> > +    }
> >       chsc_sgib(0);
> >       unregister_adapter_interrupt(&gib_alert_irq);
> >       free_page((unsigned long)gib);
> > @@ -3315,6 +3324,14 @@ int kvm_s390_gib_init(u8 nisc)
> >           goto out_unreg_gal;
> >       }
> > +    if (IS_ENABLED(CONFIG_PCI) && sclp.has_aeni) {
> > +        if (kvm_s390_pci_aen_init(nisc)) {
> > +            pr_err("Initializing AEN for PCI failed\n");
> > +            rc = -EIO;
> > +            goto out_unreg_gal;
> > +        }
> > +    }
> > +
> >       KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc);
> >       goto out;
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index 14a18ba5ff2c..9cd3c8eb59e8 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -48,6 +48,7 @@
> >   #include <asm/fpu/api.h>
> >   #include "kvm-s390.h"
> >   #include "gaccess.h"
> > +#include "pci.h"
> >   #define CREATE_TRACE_POINTS
> >   #include "trace.h"
> > @@ -503,6 +504,8 @@ int kvm_arch_init(void *opaque)
> >           goto out;
> >       }
> > +    kvm_s390_pci_init();
> > +
> >       rc = kvm_s390_gib_init(GAL_ISC);
> >       if (rc)
> >           goto out;
> > diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
> > index ecfc458a5b39..f0e5386ff943 100644
> > --- a/arch/s390/kvm/pci.c
> > +++ b/arch/s390/kvm/pci.c
> > @@ -10,6 +10,113 @@
> >   #include <linux/kvm_host.h>
> >   #include <linux/pci.h>
> >   #include <asm/kvm_pci.h>
> > +#include "pci.h"
> > +
> > +static struct zpci_aift aift;
> > +
> > +static inline int __set_irq_noiib(u16 ctl, u8 isc)
> > +{
> > +    union zpci_sic_iib iib = {{0}};
> > +
> > +    return zpci_set_irq_ctrl(ctl, isc, &iib);
> > +}
> > +
> > +struct zpci_aift *kvm_s390_pci_get_aift(void)
> > +{
> > +    return &aift;
> > +}
> > +
> > +/* Caller must hold the aift lock before calling this function */
> > +void kvm_s390_pci_aen_exit(void)
> > +{
> > +    struct zpci_gaite *gait;
> > +    unsigned long flags;
> > +    struct airq_iv *sbv;
> > +    struct kvm_zdev **gait_kzdev;
> > +    int size;
> > +
> > +    /* Clear the GAIT and forwarding summary vector */
> > +    __set_irq_noiib(SIC_SET_AENI_CONTROLS, 0);
>
> Why don't we use the PCI ISC here?

hum OK, sorry, isc is ignored for SIC_SET_AENI_CONTROLS

> ...snip...

--
Pierre Morel
IBM Lab Boeblingen