diff mbox series

[v3,3/5] s390: vfio_pci: Use a PCI Group structure

Message ID 1567815389-18229-4-git-send-email-mjrosato@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series Retrieving zPCI specific info from QEMU | expand

Commit Message

Matthew Rosato Sept. 7, 2019, 12:16 a.m. UTC 
From: Pierre Morel <pmorel@linux.ibm.com>

We use a S390PCIGroup structure to hold the information
related to zPCI Function group.

This allows us to be ready to support multiple groups and to retrieve
the group information from the host.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 hw/s390x/s390-pci-bus.c  | 42 ++++++++++++++++++++++++++++++++++++++++++
 hw/s390x/s390-pci-bus.h  | 11 ++++++++++-
 hw/s390x/s390-pci-inst.c | 22 +++++++++++++---------
 3 files changed, 65 insertions(+), 10 deletions(-)

Comments

Thomas Huth Sept. 9, 2019, 5:18 a.m. UTC | #1 
On 07/09/2019 02.16, Matthew Rosato wrote:
> From: Pierre Morel <pmorel@linux.ibm.com>
> 
> We use a S390PCIGroup structure to hold the information
> related to zPCI Function group.
> 
> This allows us to be ready to support multiple groups and to retrieve
> the group information from the host.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  hw/s390x/s390-pci-bus.c  | 42 ++++++++++++++++++++++++++++++++++++++++++
>  hw/s390x/s390-pci-bus.h  | 11 ++++++++++-
>  hw/s390x/s390-pci-inst.c | 22 +++++++++++++---------
>  3 files changed, 65 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
> index 963a41c..e625217 100644
> --- a/hw/s390x/s390-pci-bus.c
> +++ b/hw/s390x/s390-pci-bus.c
> @@ -730,6 +730,46 @@ static void s390_pci_iommu_free(S390pciState *s, PCIBus *bus, int32_t devfn)
>      object_unref(OBJECT(iommu));
>  }
>  
> +static S390PCIGroup *s390_grp_create(int ug)
> +{
> +    S390PCIGroup *grp;
> +    S390pciState *s = s390_get_phb();
> +
> +    grp = g_new0(S390PCIGroup, 1);
> +    grp->ug = ug;
> +    QTAILQ_INSERT_TAIL(&s->zpci_grps, grp, link);
> +    return grp;
> +}

Maybe an ignorant question, but shouldn't there also be some kind of
clean up function that also frees the memory again, e.g. during a
machine reset? Or are these groups supposed to survive a machine reset?

 Thomas
Matthew Rosato Sept. 9, 2019, 4:21 p.m. UTC | #2 
On 9/9/19 1:18 AM, Thomas Huth wrote:
> On 07/09/2019 02.16, Matthew Rosato wrote:
>> From: Pierre Morel <pmorel@linux.ibm.com>
>>
>> We use a S390PCIGroup structure to hold the information
>> related to zPCI Function group.
>>
>> This allows us to be ready to support multiple groups and to retrieve
>> the group information from the host.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>  hw/s390x/s390-pci-bus.c  | 42 ++++++++++++++++++++++++++++++++++++++++++
>>  hw/s390x/s390-pci-bus.h  | 11 ++++++++++-
>>  hw/s390x/s390-pci-inst.c | 22 +++++++++++++---------
>>  3 files changed, 65 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
>> index 963a41c..e625217 100644
>> --- a/hw/s390x/s390-pci-bus.c
>> +++ b/hw/s390x/s390-pci-bus.c
>> @@ -730,6 +730,46 @@ static void s390_pci_iommu_free(S390pciState *s, PCIBus *bus, int32_t devfn)
>>      object_unref(OBJECT(iommu));
>>  }
>>  
>> +static S390PCIGroup *s390_grp_create(int ug)
>> +{
>> +    S390PCIGroup *grp;
>> +    S390pciState *s = s390_get_phb();
>> +
>> +    grp = g_new0(S390PCIGroup, 1);
>> +    grp->ug = ug;
>> +    QTAILQ_INSERT_TAIL(&s->zpci_grps, grp, link);
>> +    return grp;
>> +}
> 
> Maybe an ignorant question, but shouldn't there also be some kind of
> clean up function that also frees the memory again, e.g. during a
> machine reset? Or are these groups supposed to survive a machine reset?

Hmm..  Well, I think it is in line with the way the devices themselves
are handled during reset (they are not removed during a reset unless
there was a pending unplug and their info persists).  But you have a
point in that it seems sketchy to leave the group information around,
particularly in cases where the last device associated with the group
has been unplugged.

So yes, I think there is some work to be done here.  I need to
investigate whether a precautionary wiping of the list (minus the
default group) at machine reset is really good enough or whether we need
to remove group info sooner (device unplug).

Thanks,
Matt
diff mbox series

Patch

diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 963a41c..e625217 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -730,6 +730,46 @@  static void s390_pci_iommu_free(S390pciState *s, PCIBus *bus, int32_t devfn)
     object_unref(OBJECT(iommu));
 }
 
+static S390PCIGroup *s390_grp_create(int ug)
+{
+    S390PCIGroup *grp;
+    S390pciState *s = s390_get_phb();
+
+    grp = g_new0(S390PCIGroup, 1);
+    grp->ug = ug;
+    QTAILQ_INSERT_TAIL(&s->zpci_grps, grp, link);
+    return grp;
+}
+
+S390PCIGroup *s390_grp_find(int ug)
+{
+    S390PCIGroup *grp;
+    S390pciState *s = s390_get_phb();
+
+    QTAILQ_FOREACH(grp, &s->zpci_grps, link) {
+        if ((grp->ug & CLP_REQ_QPCIG_MASK_PFGID) == ug) {
+            return grp;
+        }
+    }
+    return NULL;
+}
+
+static void s390_pci_init_default_group(void)
+{
+    S390PCIGroup *grp;
+    ClpRspQueryPciGrp *resgrp;
+
+    grp = s390_grp_create(ZPCI_DEFAULT_FN_GRP);
+    resgrp = &grp->zpci_grp;
+    resgrp->fr = 1;
+    stq_p(&resgrp->dasm, 0);
+    stq_p(&resgrp->msia, ZPCI_MSI_ADDR);
+    stw_p(&resgrp->mui, DEFAULT_MUI);
+    stw_p(&resgrp->i, 128);
+    stw_p(&resgrp->maxstbl, 128);
+    resgrp->version = 0;
+}
+
 static void s390_pcihost_realize(DeviceState *dev, Error **errp)
 {
     PCIBus *b;
@@ -766,7 +806,9 @@  static void s390_pcihost_realize(DeviceState *dev, Error **errp)
     s->bus_no = 0;
     QTAILQ_INIT(&s->pending_sei);
     QTAILQ_INIT(&s->zpci_devs);
+    QTAILQ_INIT(&s->zpci_grps);
 
+    s390_pci_init_default_group();
     css_register_io_adapters(CSS_IO_ADAPTER_PCI, true, false,
                              S390_ADAPTER_SUPPRESSIBLE, &local_err);
     error_propagate(errp, local_err);
diff --git a/hw/s390x/s390-pci-bus.h b/hw/s390x/s390-pci-bus.h
index a5d2049..e95a797 100644
--- a/hw/s390x/s390-pci-bus.h
+++ b/hw/s390x/s390-pci-bus.h
@@ -312,6 +312,14 @@  typedef struct ZpciFmb {
 } ZpciFmb;
 QEMU_BUILD_BUG_MSG(offsetof(ZpciFmb, fmt0) != 48, "padding in ZpciFmb");
 
+#define ZPCI_DEFAULT_FN_GRP 0x20
+typedef struct S390PCIGroup {
+    ClpRspQueryPciGrp zpci_grp;
+    int ug;
+    QTAILQ_ENTRY(S390PCIGroup) link;
+} S390PCIGroup;
+S390PCIGroup *s390_grp_find(int ug);
+
 struct S390PCIBusDevice {
     DeviceState qdev;
     PCIDevice *pdev;
@@ -327,8 +335,8 @@  struct S390PCIBusDevice {
     QEMUTimer *fmb_timer;
     uint8_t isc;
     uint16_t noi;
-    uint16_t maxstbl;
     uint8_t sum;
+    S390PCIGroup *pci_grp;
     S390MsixInfo msix;
     AdapterRoutes routes;
     S390PCIIOMMU *iommu;
@@ -353,6 +361,7 @@  typedef struct S390pciState {
     GHashTable *zpci_table;
     QTAILQ_HEAD(, SeiContainer) pending_sei;
     QTAILQ_HEAD(, S390PCIBusDevice) zpci_devs;
+    QTAILQ_HEAD(, S390PCIGroup) zpci_grps;
 } S390pciState;
 
 S390pciState *s390_get_phb(void);
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index 4b3bd4a..00dd176 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -284,21 +284,25 @@  int clp_service_call(S390CPU *cpu, uint8_t r2, uintptr_t ra)
         stq_p(&resquery->edma, ZPCI_EDMA_ADDR);
         stl_p(&resquery->fid, pbdev->fid);
         stw_p(&resquery->pchid, 0);
-        stw_p(&resquery->ug, 1);
+        stw_p(&resquery->ug, ZPCI_DEFAULT_FN_GRP);
         stl_p(&resquery->uid, pbdev->uid);
         stw_p(&resquery->hdr.rsp, CLP_RC_OK);
         break;
     }
     case CLP_QUERY_PCI_FNGRP: {
         ClpRspQueryPciGrp *resgrp = (ClpRspQueryPciGrp *)resh;
-        resgrp->fr = 1;
-        stq_p(&resgrp->dasm, 0);
-        stq_p(&resgrp->msia, ZPCI_MSI_ADDR);
-        stw_p(&resgrp->mui, DEFAULT_MUI);
-        stw_p(&resgrp->i, 128);
-        stw_p(&resgrp->maxstbl, 128);
-        resgrp->version = 0;
 
+        ClpReqQueryPciGrp *reqgrp = (ClpReqQueryPciGrp *)reqh;
+        S390PCIGroup *grp;
+
+        grp = s390_grp_find(reqgrp->g);
+        if (!grp) {
+            /* We do not allow access to unknown groups */
+            /* The group must have been obtained with a vfio device */
+            stw_p(&resgrp->hdr.rsp, CLP_RC_QUERYPCIFG_PFGID);
+            goto out;
+        }
+        memcpy(resgrp, &grp->zpci_grp, sizeof(ClpRspQueryPciGrp));
         stw_p(&resgrp->hdr.rsp, CLP_RC_OK);
         break;
     }
@@ -754,7 +758,7 @@  int pcistb_service_call(S390CPU *cpu, uint8_t r1, uint8_t r3, uint64_t gaddr,
     }
     /* Length must be greater than 8, a multiple of 8 */
     /* and not greater than maxstbl */
-    if ((len <= 8) || (len % 8) || (len > pbdev->maxstbl)) {
+    if ((len <= 8) || (len % 8) || (len > pbdev->pci_grp->zpci_grp.maxstbl)) {
         goto specification_error;
     }
     /* Do not cross a 4K-byte boundary */