[PATCH RFC 0/3] pci-testdev add support for kvm ioeventfd pf

[PATCH RFC 0/3] pci-testdev add support for kvm ioeventfd pf

[Michael S. Tsirkin]

This adds a test for triggering ioeventfd on pagefaults.
This was used to verify that mmio ioeventfd on pagefault is
as fast as portio.

Michael S. Tsirkin (3):
  pci-testdev: separate page for each mmio test
  pci-testdev: add subregion
  pci-testdev: add RO pages for ioeventfd

 hw/misc/pci-testdev.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

-- 
MST

[Qemu-devel] [PATCH RFC 0/3] pci-testdev add support for kvm ioeventfd pf

[Michael S. Tsirkin]

This adds a test for triggering ioeventfd on pagefaults.
This was used to verify that mmio ioeventfd on pagefault is
as fast as portio.

Michael S. Tsirkin (3):
  pci-testdev: separate page for each mmio test
  pci-testdev: add subregion
  pci-testdev: add RO pages for ioeventfd

 hw/misc/pci-testdev.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

-- 
MST

[PATCH RFC 1/3] pci-testdev: separate page for each mmio test

[Michael S. Tsirkin]

note: this makes BAR > 4K, which requires kvm unit test
patch to support such BAR. Do we need to worry about
old kvm unit test binaries? I'm guessing not ...

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pci-testdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index b6e11d6..6edc1cd 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -48,7 +48,7 @@ typedef struct IOTest {
 #define IOTEST_NODATA  0xAB
 
 #define IOTEST_IOSIZE 128
-#define IOTEST_MEMSIZE 2048
+#define IOTEST_MEMSIZE 0x10000
 
 static const char *iotest_test[] = {
     "no-eventfd",
@@ -262,7 +262,7 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
         test->hdr = g_malloc0(test->bufsize);
         memcpy(test->hdr->name, name, strlen(name) + 1);
         g_free(name);
-        test->hdr->offset = cpu_to_le32(IOTEST_SIZE(i) + i * IOTEST_ACCESS_WIDTH);
+        test->hdr->offset = cpu_to_le32(IOTEST_SIZE(i) + i * (IOTEST_IS_MEM(i) ? 0x1000 : IOTEST_ACCESS_WIDTH));
         test->size = strcmp(IOTEST_TEST(i), "nodata-eventfd") ? IOTEST_ACCESS_WIDTH : 0;
 
         test->match_data = strcmp(IOTEST_TEST(i), "wildcard-eventfd") &&
@@ -273,6 +273,7 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
         test->mr = IOTEST_REGION(d, i);
 
         if (!test->size && !IOTEST_IS_MEM(i)) {
+            test->hdr->width = 0;
             test->hasnotifier = false;
             continue;
         }
-- 
MST

[Qemu-devel] [PATCH RFC 1/3] pci-testdev: separate page for each mmio test

[Michael S. Tsirkin]

note: this makes BAR > 4K, which requires kvm unit test
patch to support such BAR. Do we need to worry about
old kvm unit test binaries? I'm guessing not ...

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pci-testdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index b6e11d6..6edc1cd 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -48,7 +48,7 @@ typedef struct IOTest {
 #define IOTEST_NODATA  0xAB
 
 #define IOTEST_IOSIZE 128
-#define IOTEST_MEMSIZE 2048
+#define IOTEST_MEMSIZE 0x10000
 
 static const char *iotest_test[] = {
     "no-eventfd",
@@ -262,7 +262,7 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
         test->hdr = g_malloc0(test->bufsize);
         memcpy(test->hdr->name, name, strlen(name) + 1);
         g_free(name);
-        test->hdr->offset = cpu_to_le32(IOTEST_SIZE(i) + i * IOTEST_ACCESS_WIDTH);
+        test->hdr->offset = cpu_to_le32(IOTEST_SIZE(i) + i * (IOTEST_IS_MEM(i) ? 0x1000 : IOTEST_ACCESS_WIDTH));
         test->size = strcmp(IOTEST_TEST(i), "nodata-eventfd") ? IOTEST_ACCESS_WIDTH : 0;
 
         test->match_data = strcmp(IOTEST_TEST(i), "wildcard-eventfd") &&
@@ -273,6 +273,7 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
         test->mr = IOTEST_REGION(d, i);
 
         if (!test->size && !IOTEST_IS_MEM(i)) {
+            test->hdr->width = 0;
             test->hasnotifier = false;
             continue;
         }
-- 
MST

[PATCH RFC 2/3] pci-testdev: add subregion

[Michael S. Tsirkin]

Make mmio a subregion of the BAR. 
This will allow mapping rom within the same BAR down the road.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pci-testdev.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index 6edc1cd..94141a3 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -83,6 +83,7 @@ typedef struct PCITestDevState {
     /*< public >*/
 
     MemoryRegion mmio;
+    MemoryRegion mbar;
     MemoryRegion portio;
     IOTest *tests;
     int current;
@@ -248,9 +249,13 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
 
     memory_region_init_io(&d->mmio, OBJECT(d), &pci_testdev_mmio_ops, d,
                           "pci-testdev-mmio", IOTEST_MEMSIZE * 2);
+    memory_region_init(&d->mbar, OBJECT(d),
+                          "pci-testdev-mmio", IOTEST_MEMSIZE * 2);
     memory_region_init_io(&d->portio, OBJECT(d), &pci_testdev_pio_ops, d,
                           "pci-testdev-portio", IOTEST_IOSIZE * 2);
-    pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
+
+    memory_region_add_subregion_overlap(&d->mbar, 0, &d->mmio, 1 /* prio */);
+    pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mbar);
     pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_SPACE_IO, &d->portio);
 
     d->current = -1;
-- 
MST

[Qemu-devel] [PATCH RFC 2/3] pci-testdev: add subregion

[Michael S. Tsirkin]

Make mmio a subregion of the BAR. 
This will allow mapping rom within the same BAR down the road.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pci-testdev.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index 6edc1cd..94141a3 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -83,6 +83,7 @@ typedef struct PCITestDevState {
     /*< public >*/
 
     MemoryRegion mmio;
+    MemoryRegion mbar;
     MemoryRegion portio;
     IOTest *tests;
     int current;
@@ -248,9 +249,13 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
 
     memory_region_init_io(&d->mmio, OBJECT(d), &pci_testdev_mmio_ops, d,
                           "pci-testdev-mmio", IOTEST_MEMSIZE * 2);
+    memory_region_init(&d->mbar, OBJECT(d),
+                          "pci-testdev-mmio", IOTEST_MEMSIZE * 2);
     memory_region_init_io(&d->portio, OBJECT(d), &pci_testdev_pio_ops, d,
                           "pci-testdev-portio", IOTEST_IOSIZE * 2);
-    pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
+
+    memory_region_add_subregion_overlap(&d->mbar, 0, &d->mmio, 1 /* prio */);
+    pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mbar);
     pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_SPACE_IO, &d->portio);
 
     d->current = -1;
-- 
MST

[PATCH RFC 3/3] pci-testdev: add RO pages for ioeventfd

[Michael S. Tsirkin]

This seems hackish - would it be better to create this region
automatically within kvm? Suggestions are welcome.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pci-testdev.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index 94141a3..55efc32 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -21,6 +21,7 @@
 #include "hw/pci/pci.h"
 #include "qemu/event_notifier.h"
 #include "qemu/osdep.h"
+#include <sys/mman.h>
 
 typedef struct PCITestDevHdr {
     uint8_t test;
@@ -82,11 +83,13 @@ typedef struct PCITestDevState {
     PCIDevice parent_obj;
     /*< public >*/
 
+    MemoryRegion zeromr;
     MemoryRegion mmio;
     MemoryRegion mbar;
     MemoryRegion portio;
     IOTest *tests;
     int current;
+    void *zero;
 } PCITestDevState;
 
 #define TYPE_PCI_TEST_DEV "pci-testdev"
@@ -242,6 +245,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
     uint8_t *pci_conf;
     char *name;
     int r, i;
+    d->zero = mmap(NULL, IOTEST_MEMSIZE * 2, PROT_READ,
+                         MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+
+    memory_region_init_ram_ptr(&d->zeromr, OBJECT(d), "pci-testdev-zero", 0x1000, d->zero);
+    memory_region_set_readonly(&d->zeromr, true);
 
     pci_conf = pci_dev->config;
 
@@ -286,6 +294,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
             test->hasnotifier = false;
             continue;
         }
+
+        if (test->hasnotifier && !test->size) {
+            memory_region_add_subregion_overlap(&d->mbar, le32_to_cpu(test->hdr->offset),
+                                                &d->zeromr, 2 /* prio */);
+        }
         r = event_notifier_init(&test->notifier, 0);
         assert(r >= 0);
         test->hasnotifier = true;
-- 
MST

[Qemu-devel] [PATCH RFC 3/3] pci-testdev: add RO pages for ioeventfd

[Michael S. Tsirkin]

This seems hackish - would it be better to create this region
automatically within kvm? Suggestions are welcome.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/misc/pci-testdev.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index 94141a3..55efc32 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -21,6 +21,7 @@
 #include "hw/pci/pci.h"
 #include "qemu/event_notifier.h"
 #include "qemu/osdep.h"
+#include <sys/mman.h>
 
 typedef struct PCITestDevHdr {
     uint8_t test;
@@ -82,11 +83,13 @@ typedef struct PCITestDevState {
     PCIDevice parent_obj;
     /*< public >*/
 
+    MemoryRegion zeromr;
     MemoryRegion mmio;
     MemoryRegion mbar;
     MemoryRegion portio;
     IOTest *tests;
     int current;
+    void *zero;
 } PCITestDevState;
 
 #define TYPE_PCI_TEST_DEV "pci-testdev"
@@ -242,6 +245,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
     uint8_t *pci_conf;
     char *name;
     int r, i;
+    d->zero = mmap(NULL, IOTEST_MEMSIZE * 2, PROT_READ,
+                         MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+
+    memory_region_init_ram_ptr(&d->zeromr, OBJECT(d), "pci-testdev-zero", 0x1000, d->zero);
+    memory_region_set_readonly(&d->zeromr, true);
 
     pci_conf = pci_dev->config;
 
@@ -286,6 +294,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
             test->hasnotifier = false;
             continue;
         }
+
+        if (test->hasnotifier && !test->size) {
+            memory_region_add_subregion_overlap(&d->mbar, le32_to_cpu(test->hdr->offset),
+                                                &d->zeromr, 2 /* prio */);
+        }
         r = event_notifier_init(&test->notifier, 0);
         assert(r >= 0);
         test->hasnotifier = true;
-- 
MST

Re: [PATCH RFC 3/3] pci-testdev: add RO pages for ioeventfd

[Gonglei]

On 2015/8/30 17:20, Michael S. Tsirkin wrote:
> This seems hackish - would it be better to create this region
> automatically within kvm? Suggestions are welcome.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/misc/pci-testdev.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
> index 94141a3..55efc32 100644
> --- a/hw/misc/pci-testdev.c
> +++ b/hw/misc/pci-testdev.c
> @@ -21,6 +21,7 @@
>  #include "hw/pci/pci.h"
>  #include "qemu/event_notifier.h"
>  #include "qemu/osdep.h"
> +#include <sys/mman.h>
>  
>  typedef struct PCITestDevHdr {
>      uint8_t test;
> @@ -82,11 +83,13 @@ typedef struct PCITestDevState {
>      PCIDevice parent_obj;
>      /*< public >*/
>  
> +    MemoryRegion zeromr;
>      MemoryRegion mmio;
>      MemoryRegion mbar;
>      MemoryRegion portio;
>      IOTest *tests;
>      int current;
> +    void *zero;
>  } PCITestDevState;
>  
>  #define TYPE_PCI_TEST_DEV "pci-testdev"
> @@ -242,6 +245,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
>      uint8_t *pci_conf;
>      char *name;
>      int r, i;
> +    d->zero = mmap(NULL, IOTEST_MEMSIZE * 2, PROT_READ,
> +                         MAP_SHARED | MAP_ANONYMOUS, -1, 0);
> +

Do we need think about hotplugging pci-testdev ? If yes, then we should release some resources
when hot-unplug a pci-testdev device:
munmap(d->zero, ...)
memory_region_del_subregion(&d->mbar, &d->mmio)
...

Regards,
-Gonglei

> +    memory_region_init_ram_ptr(&d->zeromr, OBJECT(d), "pci-testdev-zero", 0x1000, d->zero);
> +    memory_region_set_readonly(&d->zeromr, true);
>  
>      pci_conf = pci_dev->config;
>  
> @@ -286,6 +294,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
>              test->hasnotifier = false;
>              continue;
>          }
> +
> +        if (test->hasnotifier && !test->size) {
> +            memory_region_add_subregion_overlap(&d->mbar, le32_to_cpu(test->hdr->offset),
> +                                                &d->zeromr, 2 /* prio */);
> +        }
>          r = event_notifier_init(&test->notifier, 0);
>          assert(r >= 0);
>          test->hasnotifier = true;
> 

Re: [Qemu-devel] [PATCH RFC 3/3] pci-testdev: add RO pages for ioeventfd

[Gonglei]

On 2015/8/30 17:20, Michael S. Tsirkin wrote:
> This seems hackish - would it be better to create this region
> automatically within kvm? Suggestions are welcome.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/misc/pci-testdev.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
> index 94141a3..55efc32 100644
> --- a/hw/misc/pci-testdev.c
> +++ b/hw/misc/pci-testdev.c
> @@ -21,6 +21,7 @@
>  #include "hw/pci/pci.h"
>  #include "qemu/event_notifier.h"
>  #include "qemu/osdep.h"
> +#include <sys/mman.h>
>  
>  typedef struct PCITestDevHdr {
>      uint8_t test;
> @@ -82,11 +83,13 @@ typedef struct PCITestDevState {
>      PCIDevice parent_obj;
>      /*< public >*/
>  
> +    MemoryRegion zeromr;
>      MemoryRegion mmio;
>      MemoryRegion mbar;
>      MemoryRegion portio;
>      IOTest *tests;
>      int current;
> +    void *zero;
>  } PCITestDevState;
>  
>  #define TYPE_PCI_TEST_DEV "pci-testdev"
> @@ -242,6 +245,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
>      uint8_t *pci_conf;
>      char *name;
>      int r, i;
> +    d->zero = mmap(NULL, IOTEST_MEMSIZE * 2, PROT_READ,
> +                         MAP_SHARED | MAP_ANONYMOUS, -1, 0);
> +

Do we need think about hotplugging pci-testdev ? If yes, then we should release some resources
when hot-unplug a pci-testdev device:
munmap(d->zero, ...)
memory_region_del_subregion(&d->mbar, &d->mmio)
...

Regards,
-Gonglei

> +    memory_region_init_ram_ptr(&d->zeromr, OBJECT(d), "pci-testdev-zero", 0x1000, d->zero);
> +    memory_region_set_readonly(&d->zeromr, true);
>  
>      pci_conf = pci_dev->config;
>  
> @@ -286,6 +294,11 @@ static void pci_testdev_realize(PCIDevice *pci_dev, Error **errp)
>              test->hasnotifier = false;
>              continue;
>          }
> +
> +        if (test->hasnotifier && !test->size) {
> +            memory_region_add_subregion_overlap(&d->mbar, le32_to_cpu(test->hdr->offset),
> +                                                &d->zeromr, 2 /* prio */);
> +        }
>          r = event_notifier_init(&test->notifier, 0);
>          assert(r >= 0);
>          test->hasnotifier = true;
>