[Qemu-devel] [PATCH v6] s390x/pci: add common fmb

[Qemu-devel] [PATCH v6] s390x/pci: add common fmb

[Pierre Morel]

After the last review round I corrected the commit message
and use the sizeof of the target entries in the fmb_di_update()
function instead of the uint definition.

Regards,
Pierre


Yi Min Zhao (1):
  s390x/pci: add common function measurement block

 hw/s390x/s390-pci-bus.c  |   4 +-
 hw/s390x/s390-pci-bus.h  |  29 +++++++++++
 hw/s390x/s390-pci-inst.c | 133 +++++++++++++++++++++++++++++++++++++++++++++--
 hw/s390x/s390-pci-inst.h |   1 +
 4 files changed, 163 insertions(+), 4 deletions(-)

-- 
2.7.4


Changelog:

from v5:
- let the compiler calculate the sizeof target entry.

from v4:
- commit message
- use sizeof target of the fmb_do_update

from v3:
- changed commit message according to Conny's comments

In s390-pci-inst.c
- simplify the fmb_do_update() to handle
  all cases from byte to quad. (Conny)

from v2:
In s390-pci-bus:
- Initialize the FMB Format.

In s390-pci-bus.h
- re-organization of the internal counters, having a table for the
  internal counters.

In s390-pci-inst.c
- Internal counters update (LD/ST/STB/RPCIT) is done always.
  even if the FMB if fmb_addr is NULL.
  AFAIU this respect the documentation which only states that FMB
  update is stopped.
- in mpcifc_service_call(), moved the setting of fmb_addr after
  the timer has been stopped.
- fmb_update((), use address_space_stq_be() to handle endianness
  when storing the FMB.
- define the format with 32 bits instead of one char and reserved
  chars, this is easier to handle the FMB copy.
- No update of the DMA fields inside the FMB, as stipulated by the
  documentation when format32 is 0.

[Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[Pierre Morel]

From: Yi Min Zhao <zyimin@linux.ibm.com>

Common function measurement block is used to report zPCI internal
counters of successful pcilg/stg/stb and rpcit instructions to
a memory location provided by the program.

This patch introduces a new ZpciFmb structure and schedules a timer
callback to copy the zPCI measures to the FMB in the guest memory
at an interval time set to 4s.

An error while attemping to update the FMB, would generate an error
event to the guest.

The pcilg/stg/stb and rpcit interception handlers increase the
related counter on a successful call.
The guest shall pass a null FMBA (FMB address) in the FIB (Function
Information Block) when it issues a Modify PCI Function Control
instruction to switch off FMB and stop the corresponding timer.

Signed-off-by: Yi Min Zhao <zyimin@linux.ibm.com>
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 hw/s390x/s390-pci-bus.c  |   4 +-
 hw/s390x/s390-pci-bus.h  |  29 +++++++++++
 hw/s390x/s390-pci-inst.c | 133 +++++++++++++++++++++++++++++++++++++++++++++--
 hw/s390x/s390-pci-inst.h |   1 +
 4 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 060ff06..f0d34dd 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -989,6 +989,7 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev,
     bus = pci_get_bus(pci_dev);
     devfn = pci_dev->devfn;
     object_unparent(OBJECT(pci_dev));
+    fmb_timer_free(pbdev);
     s390_pci_msix_free(pbdev);
     s390_pci_iommu_free(s, bus, devfn);
     pbdev->pdev = NULL;
@@ -1136,6 +1137,7 @@ static void s390_pci_device_realize(DeviceState *dev, Error **errp)
     }
 
     zpci->state = ZPCI_FS_RESERVED;
+    zpci->fmb.format = ZPCI_FMB_FORMAT;
 }
 
 static void s390_pci_device_reset(DeviceState *dev)
@@ -1160,7 +1162,7 @@ static void s390_pci_device_reset(DeviceState *dev)
         pci_dereg_ioat(pbdev->iommu);
     }
 
-    pbdev->fmb_addr = 0;
+    fmb_timer_free(pbdev);
 }
 
 static void s390_pci_get_fid(Object *obj, Visitor *v, const char *name,
diff --git a/hw/s390x/s390-pci-bus.h b/hw/s390x/s390-pci-bus.h
index 1f7f9b5..69353ef 100644
--- a/hw/s390x/s390-pci-bus.h
+++ b/hw/s390x/s390-pci-bus.h
@@ -286,6 +286,33 @@ typedef struct S390PCIIOMMUTable {
     S390PCIIOMMU *iommu[PCI_SLOT_MAX];
 } S390PCIIOMMUTable;
 
+/* Function Measurement Block */
+#define DEFAULT_MUI 4000
+#define UPDATE_U_BIT 0x1ULL
+#define FMBK_MASK 0xfULL
+
+typedef struct ZpciFmbFmt0 {
+    uint64_t dma_rbytes;
+    uint64_t dma_wbytes;
+} ZpciFmbFmt0;
+
+#define ZPCI_FMB_CNT_LD    0
+#define ZPCI_FMB_CNT_ST    1
+#define ZPCI_FMB_CNT_STB   2
+#define ZPCI_FMB_CNT_RPCIT 3
+#define ZPCI_FMB_CNT_MAX   4
+
+#define ZPCI_FMB_FORMAT    0
+
+typedef struct ZpciFmb {
+    uint32_t format;
+    uint32_t sample;
+    uint64_t last_update;
+    uint64_t counter[ZPCI_FMB_CNT_MAX];
+    ZpciFmbFmt0 fmt0;
+} ZpciFmb;
+QEMU_BUILD_BUG_MSG(offsetof(ZpciFmb, fmt0) != 48, "padding in ZpciFmb");
+
 struct S390PCIBusDevice {
     DeviceState qdev;
     PCIDevice *pdev;
@@ -297,6 +324,8 @@ struct S390PCIBusDevice {
     uint32_t fid;
     bool fid_defined;
     uint64_t fmb_addr;
+    ZpciFmb fmb;
+    QEMUTimer *fmb_timer;
     uint8_t isc;
     uint16_t noi;
     uint16_t maxstbl;
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index 7b61367..b43ac0a 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -19,6 +19,7 @@
 #include "exec/memory-internal.h"
 #include "qemu/error-report.h"
 #include "sysemu/hw_accel.h"
+#include "hw/s390x/tod.h"
 
 #ifndef DEBUG_S390PCI_INST
 #define DEBUG_S390PCI_INST  0
@@ -293,7 +294,7 @@ int clp_service_call(S390CPU *cpu, uint8_t r2, uintptr_t ra)
         resgrp->fr = 1;
         stq_p(&resgrp->dasm, 0);
         stq_p(&resgrp->msia, ZPCI_MSI_ADDR);
-        stw_p(&resgrp->mui, 0);
+        stw_p(&resgrp->mui, DEFAULT_MUI);
         stw_p(&resgrp->i, 128);
         stw_p(&resgrp->maxstbl, 128);
         resgrp->version = 0;
@@ -456,6 +457,8 @@ int pcilg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra)
         return 0;
     }
 
+    pbdev->fmb.counter[ZPCI_FMB_CNT_LD]++;
+
     env->regs[r1] = data;
     setcc(cpu, ZPCI_PCI_LS_OK);
     return 0;
@@ -561,6 +564,8 @@ int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra)
         return 0;
     }
 
+    pbdev->fmb.counter[ZPCI_FMB_CNT_ST]++;
+
     setcc(cpu, ZPCI_PCI_LS_OK);
     return 0;
 }
@@ -681,6 +686,7 @@ err:
         s390_set_status_code(env, r1, ZPCI_PCI_ST_FUNC_IN_ERR);
         s390_pci_generate_error_event(error, pbdev->fh, pbdev->fid, start, 0);
     } else {
+        pbdev->fmb.counter[ZPCI_FMB_CNT_RPCIT]++;
         setcc(cpu, ZPCI_PCI_LS_OK);
     }
     return 0;
@@ -783,6 +789,8 @@ int pcistb_service_call(S390CPU *cpu, uint8_t r1, uint8_t r3, uint64_t gaddr,
         }
     }
 
+    pbdev->fmb.counter[ZPCI_FMB_CNT_STB]++;
+
     setcc(cpu, ZPCI_PCI_LS_OK);
     return 0;
 
@@ -889,6 +897,99 @@ void pci_dereg_ioat(S390PCIIOMMU *iommu)
     iommu->g_iota = 0;
 }
 
+void fmb_timer_free(S390PCIBusDevice *pbdev)
+{
+    if (pbdev->fmb_timer) {
+        timer_del(pbdev->fmb_timer);
+        timer_free(pbdev->fmb_timer);
+        pbdev->fmb_timer = NULL;
+    }
+    pbdev->fmb_addr = 0;
+    memset(&pbdev->fmb, 0, sizeof(ZpciFmb));
+}
+
+static int fmb_do_update(S390PCIBusDevice *pbdev, int offset, uint64_t val,
+                         int len)
+{
+    MemTxResult ret;
+    uint64_t dst = pbdev->fmb_addr + offset;
+
+    switch (len) {
+    case 8:
+        address_space_stq_be(&address_space_memory, dst, val,
+                             MEMTXATTRS_UNSPECIFIED,
+                             &ret);
+        break;
+    case 4:
+        address_space_stl_be(&address_space_memory, dst, val,
+                             MEMTXATTRS_UNSPECIFIED,
+                             &ret);
+        break;
+    case 2:
+        address_space_stw_be(&address_space_memory, dst, val,
+                             MEMTXATTRS_UNSPECIFIED,
+                             &ret);
+        break;
+    case 1:
+        address_space_stb(&address_space_memory, dst, val,
+                          MEMTXATTRS_UNSPECIFIED,
+                          &ret);
+        break;
+    default:
+        ret = MEMTX_ERROR;
+        break;
+    }
+    if (ret != MEMTX_OK) {
+        s390_pci_generate_error_event(ERR_EVENT_FMBA, pbdev->fh, pbdev->fid,
+                                      pbdev->fmb_addr, 0);
+        fmb_timer_free(pbdev);
+    }
+
+    return ret;
+}
+
+static void fmb_update(void *opaque)
+{
+    S390PCIBusDevice *pbdev = opaque;
+    int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
+    int i;
+
+    /* Update U bit */
+    pbdev->fmb.last_update *= 2;
+    pbdev->fmb.last_update |= UPDATE_U_BIT;
+    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
+                      pbdev->fmb.last_update,
+                      sizeof(((ZpciFmb *)0)->last_update))) {
+        return;
+    }
+
+    /* Update FMB sample count */
+    if (fmb_do_update(pbdev, offsetof(ZpciFmb, sample),
+                      pbdev->fmb.sample++,
+                      sizeof(((ZpciFmb *)0)->sample))) {
+        return;
+    }
+
+    /* Update FMB counters */
+    for (i = 0; i < ZPCI_FMB_CNT_MAX; i++) {
+        if (fmb_do_update(pbdev, offsetof(ZpciFmb, counter[i]),
+                          pbdev->fmb.counter[i],
+                          sizeof(((ZpciFmb *)0)->counter[0]))) {
+            return;
+        }
+    }
+
+    /* Clear U bit and update the time */
+    pbdev->fmb.last_update = time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+    pbdev->fmb.last_update *= 2;
+    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
+                      pbdev->fmb.last_update,
+                      sizeof(((ZpciFmb *)0)->last_update))) {
+        return;
+    }
+    timer_mod(pbdev->fmb_timer, t + DEFAULT_MUI);
+}
+
 int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
                         uintptr_t ra)
 {
@@ -1018,9 +1119,35 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         }
         break;
-    case ZPCI_MOD_FC_SET_MEASURE:
-        pbdev->fmb_addr = ldq_p(&fib.fmb_addr);
+    case ZPCI_MOD_FC_SET_MEASURE: {
+        uint64_t fmb_addr = ldq_p(&fib.fmb_addr);
+
+        if (fmb_addr & FMBK_MASK) {
+            cc = ZPCI_PCI_LS_ERR;
+            s390_pci_generate_error_event(ERR_EVENT_FMBPRO, pbdev->fh,
+                                          pbdev->fid, fmb_addr, 0);
+            fmb_timer_free(pbdev);
+            break;
+        }
+
+        if (!fmb_addr) {
+            /* Stop updating FMB. */
+            fmb_timer_free(pbdev);
+            break;
+        }
+
+        if (!pbdev->fmb_timer) {
+            pbdev->fmb_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
+                                            fmb_update, pbdev);
+        } else if (timer_pending(pbdev->fmb_timer)) {
+            /* Remove pending timer to update FMB address. */
+            timer_del(pbdev->fmb_timer);
+        }
+        pbdev->fmb_addr = fmb_addr;
+        timer_mod(pbdev->fmb_timer,
+                  qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + DEFAULT_MUI);
         break;
+    }
     default:
         s390_program_interrupt(&cpu->env, PGM_OPERAND, 6, ra);
         cc = ZPCI_PCI_LS_ERR;
diff --git a/hw/s390x/s390-pci-inst.h b/hw/s390x/s390-pci-inst.h
index 91c3d61..fa3bf8b 100644
--- a/hw/s390x/s390-pci-inst.h
+++ b/hw/s390x/s390-pci-inst.h
@@ -303,6 +303,7 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
                         uintptr_t ra);
 int stpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
                          uintptr_t ra);
+void fmb_timer_free(S390PCIBusDevice *pbdev);
 
 #define ZPCI_IO_BAR_MIN 0
 #define ZPCI_IO_BAR_MAX 5
-- 
2.7.4

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[Cornelia Huck]

On Thu,  3 Jan 2019 11:17:00 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:

> +static void fmb_update(void *opaque)
> +{
> +    S390PCIBusDevice *pbdev = opaque;
> +    int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
> +    int i;
> +
> +    /* Update U bit */
> +    pbdev->fmb.last_update *= 2;
> +    pbdev->fmb.last_update |= UPDATE_U_BIT;
> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
> +                      pbdev->fmb.last_update,
> +                      sizeof(((ZpciFmb *)0)->last_update))) {

I really don't want to be a pain, but... this looks weird. Why not
simply sizeof(pbdev->fmb.last_update)?

> +        return;
> +    }
> +
> +    /* Update FMB sample count */
> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, sample),
> +                      pbdev->fmb.sample++,
> +                      sizeof(((ZpciFmb *)0)->sample))) {
> +        return;
> +    }
> +
> +    /* Update FMB counters */
> +    for (i = 0; i < ZPCI_FMB_CNT_MAX; i++) {
> +        if (fmb_do_update(pbdev, offsetof(ZpciFmb, counter[i]),
> +                          pbdev->fmb.counter[i],
> +                          sizeof(((ZpciFmb *)0)->counter[0]))) {
> +            return;
> +        }
> +    }
> +
> +    /* Clear U bit and update the time */
> +    pbdev->fmb.last_update = time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +    pbdev->fmb.last_update *= 2;
> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
> +                      pbdev->fmb.last_update,
> +                      sizeof(((ZpciFmb *)0)->last_update))) {
> +        return;
> +    }
> +    timer_mod(pbdev->fmb_timer, t + DEFAULT_MUI);
> +}
> +

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[Pierre Morel]

On 04/01/2019 15:39, Cornelia Huck wrote:
> On Thu,  3 Jan 2019 11:17:00 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> +static void fmb_update(void *opaque)
>> +{
>> +    S390PCIBusDevice *pbdev = opaque;
>> +    int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
>> +    int i;
>> +
>> +    /* Update U bit */
>> +    pbdev->fmb.last_update *= 2;
>> +    pbdev->fmb.last_update |= UPDATE_U_BIT;
>> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
>> +                      pbdev->fmb.last_update,
>> +                      sizeof(((ZpciFmb *)0)->last_update))) {
> 
> I really don't want to be a pain, but... this looks weird. Why not
> simply sizeof(pbdev->fmb.last_update)?

Isn't it preferable to use the size of the destination?

Regards,
Pierre

-- 
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[Thomas Huth]

On 2019-01-07 10:08, Pierre Morel wrote:
> On 04/01/2019 15:39, Cornelia Huck wrote:
>> On Thu,  3 Jan 2019 11:17:00 +0100
>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>
>>> +static void fmb_update(void *opaque)
>>> +{
>>> +    S390PCIBusDevice *pbdev = opaque;
>>> +    int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
>>> +    int i;
>>> +
>>> +    /* Update U bit */
>>> +    pbdev->fmb.last_update *= 2;
>>> +    pbdev->fmb.last_update |= UPDATE_U_BIT;
>>> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
>>> +                      pbdev->fmb.last_update,
>>> +                      sizeof(((ZpciFmb *)0)->last_update))) {
>>
>> I really don't want to be a pain, but... this looks weird. Why not
>> simply sizeof(pbdev->fmb.last_update)?
> 
> Isn't it preferable to use the size of the destination?

But "(ZpciFmb *)0" in the context of QEMU isn't the destination either,
it's an invalid pointer. So I think I agree with Cornelia,
"sizeof(pbdev->fmb.last_update)" looks much easier to read and
understand here.

 Thomas

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[Pierre Morel]

On 07/01/2019 10:11, Thomas Huth wrote:
> On 2019-01-07 10:08, Pierre Morel wrote:
>> On 04/01/2019 15:39, Cornelia Huck wrote:
>>> On Thu,  3 Jan 2019 11:17:00 +0100
>>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>>
>>>> +static void fmb_update(void *opaque)
>>>> +{
>>>> +    S390PCIBusDevice *pbdev = opaque;
>>>> +    int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
>>>> +    int i;
>>>> +
>>>> +    /* Update U bit */
>>>> +    pbdev->fmb.last_update *= 2;
>>>> +    pbdev->fmb.last_update |= UPDATE_U_BIT;
>>>> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
>>>> +                      pbdev->fmb.last_update,
>>>> +                      sizeof(((ZpciFmb *)0)->last_update))) {
>>>
>>> I really don't want to be a pain, but... this looks weird. Why not
>>> simply sizeof(pbdev->fmb.last_update)?
>>
>> Isn't it preferable to use the size of the destination?
> 
> But "(ZpciFmb *)0" in the context of QEMU isn't the destination either,
> it's an invalid pointer. So I think I agree with Cornelia,
> "sizeof(pbdev->fmb.last_update)" looks much easier to read and
> understand here.
> 
>   Thomas
> 
> 

sizeof() returns the field length, the pointer value is not relevant.
But I will do as you wish if you both prefer to use this.
Anyway, this should be the same.

regards,
Pierre

-- 
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[David Hildenbrand]

On 03.01.19 11:17, Pierre Morel wrote:
> From: Yi Min Zhao <zyimin@linux.ibm.com>
> 
> Common function measurement block is used to report zPCI internal
> counters of successful pcilg/stg/stb and rpcit instructions to
> a memory location provided by the program.
> 
> This patch introduces a new ZpciFmb structure and schedules a timer
> callback to copy the zPCI measures to the FMB in the guest memory
> at an interval time set to 4s.
> 
> An error while attemping to update the FMB, would generate an error
> event to the guest.
> 
> The pcilg/stg/stb and rpcit interception handlers increase the
> related counter on a successful call.
> The guest shall pass a null FMBA (FMB address) in the FIB (Function
> Information Block) when it issues a Modify PCI Function Control
> instruction to switch off FMB and stop the corresponding timer.
> 
> Signed-off-by: Yi Min Zhao <zyimin@linux.ibm.com>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  hw/s390x/s390-pci-bus.c  |   4 +-
>  hw/s390x/s390-pci-bus.h  |  29 +++++++++++
>  hw/s390x/s390-pci-inst.c | 133 +++++++++++++++++++++++++++++++++++++++++++++--
>  hw/s390x/s390-pci-inst.h |   1 +
>  4 files changed, 163 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
> index 060ff06..f0d34dd 100644
> --- a/hw/s390x/s390-pci-bus.c
> +++ b/hw/s390x/s390-pci-bus.c
> @@ -989,6 +989,7 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev,
>      bus = pci_get_bus(pci_dev);
>      devfn = pci_dev->devfn;
>      object_unparent(OBJECT(pci_dev));
> +    fmb_timer_free(pbdev);

I wonder if this should go into the unrealize function instead.



-- 

Thanks,

David / dhildenb

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[Pierre Morel]

On 07/01/2019 12:30, David Hildenbrand wrote:
> On 03.01.19 11:17, Pierre Morel wrote:
>> From: Yi Min Zhao <zyimin@linux.ibm.com>
>>
>> Common function measurement block is used to report zPCI internal
>> counters of successful pcilg/stg/stb and rpcit instructions to
>> a memory location provided by the program.
>>
>> This patch introduces a new ZpciFmb structure and schedules a timer
>> callback to copy the zPCI measures to the FMB in the guest memory
>> at an interval time set to 4s.
>>
>> An error while attemping to update the FMB, would generate an error
>> event to the guest.
>>
>> The pcilg/stg/stb and rpcit interception handlers increase the
>> related counter on a successful call.
>> The guest shall pass a null FMBA (FMB address) in the FIB (Function
>> Information Block) when it issues a Modify PCI Function Control
>> instruction to switch off FMB and stop the corresponding timer.
>>
>> Signed-off-by: Yi Min Zhao <zyimin@linux.ibm.com>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   hw/s390x/s390-pci-bus.c  |   4 +-
>>   hw/s390x/s390-pci-bus.h  |  29 +++++++++++
>>   hw/s390x/s390-pci-inst.c | 133 +++++++++++++++++++++++++++++++++++++++++++++--
>>   hw/s390x/s390-pci-inst.h |   1 +
>>   4 files changed, 163 insertions(+), 4 deletions(-)
>>
>> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
>> index 060ff06..f0d34dd 100644
>> --- a/hw/s390x/s390-pci-bus.c
>> +++ b/hw/s390x/s390-pci-bus.c
>> @@ -989,6 +989,7 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev,
>>       bus = pci_get_bus(pci_dev);
>>       devfn = pci_dev->devfn;
>>       object_unparent(OBJECT(pci_dev));
>> +    fmb_timer_free(pbdev);
> 
> I wonder if this should go into the unrealize function instead.
> 
> 
> 

What make you think it should?
All zPCI specific resources are free inside the hot_unplug callback.
Why should the timer be handled differently?

The timer is not setup during realize, but later on a guest request.

AFAIK unrealize would be called after the unplug handler or is there a 
case for which unrealize would be called and not the hotplug handler?

Regards,
Pierre


-- 
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany

Re: [Qemu-devel] [PATCH v6] s390x/pci: add common function measurement block

[David Hildenbrand]

On 08.01.19 18:29, Pierre Morel wrote:
> On 07/01/2019 12:30, David Hildenbrand wrote:
>> On 03.01.19 11:17, Pierre Morel wrote:
>>> From: Yi Min Zhao <zyimin@linux.ibm.com>
>>>
>>> Common function measurement block is used to report zPCI internal
>>> counters of successful pcilg/stg/stb and rpcit instructions to
>>> a memory location provided by the program.
>>>
>>> This patch introduces a new ZpciFmb structure and schedules a timer
>>> callback to copy the zPCI measures to the FMB in the guest memory
>>> at an interval time set to 4s.
>>>
>>> An error while attemping to update the FMB, would generate an error
>>> event to the guest.
>>>
>>> The pcilg/stg/stb and rpcit interception handlers increase the
>>> related counter on a successful call.
>>> The guest shall pass a null FMBA (FMB address) in the FIB (Function
>>> Information Block) when it issues a Modify PCI Function Control
>>> instruction to switch off FMB and stop the corresponding timer.
>>>
>>> Signed-off-by: Yi Min Zhao <zyimin@linux.ibm.com>
>>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>>> ---
>>>   hw/s390x/s390-pci-bus.c  |   4 +-
>>>   hw/s390x/s390-pci-bus.h  |  29 +++++++++++
>>>   hw/s390x/s390-pci-inst.c | 133 +++++++++++++++++++++++++++++++++++++++++++++--
>>>   hw/s390x/s390-pci-inst.h |   1 +
>>>   4 files changed, 163 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
>>> index 060ff06..f0d34dd 100644
>>> --- a/hw/s390x/s390-pci-bus.c
>>> +++ b/hw/s390x/s390-pci-bus.c
>>> @@ -989,6 +989,7 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev,
>>>       bus = pci_get_bus(pci_dev);
>>>       devfn = pci_dev->devfn;
>>>       object_unparent(OBJECT(pci_dev));
>>> +    fmb_timer_free(pbdev);
>>
>> I wonder if this should go into the unrealize function instead.
>>
>>
>>
> 
> What make you think it should?
> All zPCI specific resources are free inside the hot_unplug callback.
> Why should the timer be handled differently?

Just because it is like that nowadays doesn't mean it is correct :)

> 
> The timer is not setup during realize, but later on a guest request.
> 
> AFAIK unrealize would be called after the unplug handler or is there a 
> case for which unrealize would be called and not the hotplug handler?

The unplug handler really only is there to unassign resources previously
assigned by the hotplug handler (and to eventually unrealize + free the
device). Using it for other purposes is usually logically wrong.
(unrealize/finalize is the right place for such things)

> 
> Regards,
> Pierre
> 
> 


-- 

Thanks,

David / dhildenb