[Qemu-devel] [PATCH 0/4] s390-ccw.img: Some more updates.

[Qemu-devel] [PATCH 0/4] s390-ccw.img: Some more updates.

[Cornelia Huck]

Some changes I hacked up quickly for the ccw loader.

Only compile tested as my main test system is currently unavailable.

Cornelia Huck (4):
  s390-ccw.img: Detect devices with stsch.
  s390-ccw.img: Enhance drain_irqs().
  s390-ccw.img: Rudimentary error checking.
  s390-ccw.img: Get queue config from host.

 pc-bios/s390-ccw/main.c   |  9 +++++---
 pc-bios/s390-ccw/virtio.c | 52 ++++++++++++++++++++++++++++++++++++-----------
 pc-bios/s390-ccw/virtio.h |  5 +++++
 3 files changed, 51 insertions(+), 15 deletions(-)

-- 
1.7.12.4

[Qemu-devel] [PATCH 1/4] s390-ccw.img: Detect devices with stsch.

[Cornelia Huck]

stsch is the canonical way to detect devices. As a bonus, we can
abort the loop if we get cc 3, and we need to check only the valid
devices (dnv set).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 pc-bios/s390-ccw/main.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 67f4987..fd40fa5 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -22,7 +22,7 @@ void virtio_panic(const char *string)
 
 static void virtio_setup(void)
 {
-    struct irb irb;
+    struct schib schib;
     int i;
     int r;
     bool found = false;
@@ -31,8 +31,11 @@ static void virtio_setup(void)
 
     for (i = 0; i < 0x10000; i++) {
         blk_schid.sch_no = i;
-        r = tsch(blk_schid, &irb);
-        if (r != 3) {
+        r = stsch_err(blk_schid, &schib);
+        if (r == 3) {
+            break;
+        }
+        if (schib.pmcw.dnv) {
             if (virtio_is_blk(blk_schid)) {
                 found = true;
                 break;
-- 
1.7.12.4

[Qemu-devel] [PATCH 2/4] s390-ccw.img: Enhance drain_irqs().

[Cornelia Huck]

- Use tpi + tsch to get interrupts.
- Return an error if the irb indicates problems.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 pc-bios/s390-ccw/virtio.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index 79e2941..2a132f8 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -38,12 +38,27 @@ static void virtio_notify(struct subchannel_id schid)
  *             Virtio functions                *
  ***********************************************/
 
-static void drain_irqs(struct subchannel_id schid)
+static int drain_irqs(struct subchannel_id schid)
 {
     struct irb irb = {};
+    struct tpi_info tpi_info = {};
+    int r = 0;
+
     while (1) {
-        if (tsch(schid, &irb)) {
-            return;
+        if (tpi(&tpi_info)) {
+            if (tpi_info.schid.sch_no != schid.sch_no) {
+                /* should not really happen... */
+                continue;
+            }
+            if (tsch(schid, &irb)) {
+                /* Might want to differentiate error codes later on. */
+                if (irb.scsw.cstat) {
+                    r = -EIO;
+                } else if (irb.scsw.dstat != 0xc) {
+                    r = -EIO;
+                }
+                return r;
+            }
         }
     }
 }
-- 
1.7.12.4

[Qemu-devel] [PATCH 3/4] s390-ccw.img: Rudimentary error checking.

[Cornelia Huck]

Try to handle at least some of the errors that may happen.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 pc-bios/s390-ccw/virtio.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index 2a132f8..8e37dce 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -90,7 +90,9 @@ static int run_ccw(struct subchannel_id schid, int cmd, void *ptr, int len)
      *     assume that a simple tsch will have finished the CCW processing,
      *     but the architecture allows for asynchronous operation
      */
-    drain_irqs(schid);
+    if (!r) {
+        r = drain_irqs(schid);
+    }
     return r;
 }
 
@@ -98,7 +100,9 @@ static void virtio_set_status(struct subchannel_id schid,
                               unsigned long dev_addr)
 {
     unsigned char status = dev_addr;
-    run_ccw(schid, CCW_CMD_WRITE_STATUS, &status, sizeof(status));
+    if (run_ccw(schid, CCW_CMD_WRITE_STATUS, &status, sizeof(status))) {
+        virtio_panic("Could not write status to host!\n");
+    }
 }
 
 static void virtio_reset(struct subchannel_id schid)
@@ -197,6 +201,7 @@ static int virtio_read_many(ulong sector, void *load_addr, int sec_num)
 {
     struct virtio_blk_outhdr out_hdr;
     u8 status;
+    int r;
 
     /* Tell the host we want to read */
     out_hdr.type = VIRTIO_BLK_T_IN;
@@ -217,8 +222,11 @@ static int virtio_read_many(ulong sector, void *load_addr, int sec_num)
     /* Now we can tell the host to read */
     vring_wait_reply(&block, 0);
 
-    drain_irqs(block.schid);
-
+    r = drain_irqs(block.schid);
+    if (r) {
+        /* Well, whatever status is supposed to contain... */
+        status = 1;
+    }
     return status;
 }
 
@@ -266,8 +274,9 @@ void virtio_setup_block(struct subchannel_id schid)
     info.num = 128;
     block.schid = schid;
 
-    run_ccw(schid, CCW_CMD_SET_VQ, &info, sizeof(info));
-    virtio_set_status(schid, VIRTIO_CONFIG_S_DRIVER_OK);
+    if (!run_ccw(schid, CCW_CMD_SET_VQ, &info, sizeof(info))) {
+        virtio_set_status(schid, VIRTIO_CONFIG_S_DRIVER_OK);
+    }
 }
 
 bool virtio_is_blk(struct subchannel_id schid)
-- 
1.7.12.4

[Qemu-devel] [PATCH 4/4] s390-ccw.img: Get queue config from host.

[Cornelia Huck]

Ask the host about the configuration instead of guessing it.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 pc-bios/s390-ccw/virtio.c | 10 +++++++---
 pc-bios/s390-ccw/virtio.h |  5 +++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index 8e37dce..6b28aab 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -261,17 +261,21 @@ int virtio_read(ulong sector, void *load_addr)
 void virtio_setup_block(struct subchannel_id schid)
 {
     struct vq_info_block info;
+    struct vq_config_block config = {};
 
     virtio_reset(schid);
 
-    /* XXX need to fetch the 128 from host */
-    vring_init(&block, 128, (void*)(100 * 1024 * 1024),
+    config.index = 0;
+    if (run_ccw(schid, CCW_CMD_READ_VQ_CONF, &config, sizeof(config))) {
+        virtio_panic("Could not get block device configuration\n");
+    }
+    vring_init(&block, config.num, (void*)(100 * 1024 * 1024),
                KVM_S390_VIRTIO_RING_ALIGN);
 
     info.queue = (100ULL * 1024ULL* 1024ULL);
     info.align = KVM_S390_VIRTIO_RING_ALIGN;
     info.index = 0;
-    info.num = 128;
+    info.num = config.num;
     block.schid = schid;
 
     if (!run_ccw(schid, CCW_CMD_SET_VQ, &info, sizeof(info))) {
diff --git a/pc-bios/s390-ccw/virtio.h b/pc-bios/s390-ccw/virtio.h
index a33199d..86fdd57 100644
--- a/pc-bios/s390-ccw/virtio.h
+++ b/pc-bios/s390-ccw/virtio.h
@@ -53,6 +53,11 @@ struct vq_info_block {
     u16 num;
 } __attribute__((packed));
 
+struct vq_config_block {
+    u16 index;
+    u16 num;
+} __attribute__((packed));
+
 struct virtio_dev {
     struct virtio_dev_header *header;
     struct virtio_vqconfig *vqconfig;
-- 
1.7.12.4

Re: [Qemu-devel] [PATCH 0/4] s390-ccw.img: Some more updates.

[Alexander Graf]

On 23.04.2013, at 14:37, Cornelia Huck wrote:

> Some changes I hacked up quickly for the ccw loader.
> 
> Only compile tested as my main test system is currently unavailable.

Yup, doesn't work :)


Alex