diff mbox series

[v11,12/19] multi-process: Forward PCI config space acceses to the remote process

Message ID 1a1490ba03686fe29a0f627bec1556a0051fed18.1602784930.git.jag.raman@oracle.com (mailing list archive)
State New, archived
Headers show
Series Initial support for multi-process Qemu | expand

Commit Message

Jag Raman Oct. 15, 2020, 6:05 p.m. UTC 
From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

The Proxy Object sends the PCI config space accesses as messages
to the remote process over the communication channel

TODO:
Investigate if the local PCI config writes can be dropped.
Without the proxy local PCI config space writes for the device,
the driver in the guest times out on the probing.
We have tried to only refer to the remote for the PCI config writes,
but the driver timeout in the guest forced as to left this
as it is (removing local PCI config only).

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/i386/remote-msg.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
 hw/pci/proxy.c           | 50 ++++++++++++++++++++++++++++++++++++++
 include/io/mpqemu-link.h |  9 +++++++
 io/mpqemu-link.c         |  6 +++++
 4 files changed, 127 insertions(+)

Comments

Philippe Mathieu-Daudé Oct. 23, 2020, 4:59 p.m. UTC | #1 
On 10/15/20 8:05 PM, Jagannathan Raman wrote:
> From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> 
> The Proxy Object sends the PCI config space accesses as messages
> to the remote process over the communication channel
> 
> TODO:
> Investigate if the local PCI config writes can be dropped.
> Without the proxy local PCI config space writes for the device,
> the driver in the guest times out on the probing.
> We have tried to only refer to the remote for the PCI config writes,
> but the driver timeout in the guest forced as to left this
> as it is (removing local PCI config only).

I expect this TODO to be lost in git history. Better to
commit it in the code and remove it once resolved IMHO.

> 
> Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
> Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   hw/i386/remote-msg.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++
>   hw/pci/proxy.c           | 50 ++++++++++++++++++++++++++++++++++++++
>   include/io/mpqemu-link.h |  9 +++++++
>   io/mpqemu-link.c         |  6 +++++
>   4 files changed, 127 insertions(+)

Please have a look at scripts/git.orderfile, it helps
reviewers to avoid scrolling down/up the patches.

> 
> diff --git a/hw/i386/remote-msg.c b/hw/i386/remote-msg.c
> index 6451b77..94937db 100644
> --- a/hw/i386/remote-msg.c
> +++ b/hw/i386/remote-msg.c
> @@ -15,6 +15,12 @@
>   #include "io/mpqemu-link.h"
>   #include "qapi/error.h"
>   #include "sysemu/runstate.h"
> +#include "hw/pci/pci.h"
> +
> +static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
> +                                 MPQemuMsg *msg);
> +static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
> +                                MPQemuMsg *msg);
>   
>   void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
>   {
> @@ -43,6 +49,12 @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
>           }
>   
>           switch (msg.cmd) {
> +        case PCI_CONFIG_WRITE:
> +            process_config_write(com->ioc, pci_dev, &msg);
> +            break;
> +        case PCI_CONFIG_READ:
> +            process_config_read(com->ioc, pci_dev, &msg);
> +            break;
>           default:
>               error_setg(&local_err,
>                          "Unknown command (%d) received for device %s (pid=%d)",
> @@ -60,3 +72,53 @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
>   
>       return;
>   }
> +
> +static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
> +                                 MPQemuMsg *msg)
> +{
> +    ConfDataMsg *conf = (ConfDataMsg *)&msg->data.conf_data;
> +    MPQemuMsg ret = { 0 };
> +    Error *local_err = NULL;
> +
> +    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
> +        error_report("Bad address received when writing PCI config, pid %d",
> +                     getpid());
> +        ret.data.u64 = UINT64_MAX;
> +    } else {
> +        pci_default_write_config(dev, conf->addr, conf->val, conf->l);
> +    }
> +
> +    ret.cmd = RET_MSG;
> +    ret.size = sizeof(ret.data.u64);
> +
> +    mpqemu_msg_send(&ret, ioc, &local_err);
> +    if (local_err) {
> +        error_report("Could not send message to proxy from pid %d",
> +                     getpid());
> +    }
> +}
> +
> +static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
> +                                MPQemuMsg *msg)
> +{
> +    ConfDataMsg *conf = (ConfDataMsg *)&msg->data.conf_data;
> +    MPQemuMsg ret = { 0 };
> +    Error *local_err = NULL;
> +
> +    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
> +        error_report("Bad address received when reading PCI config, pid %d",
> +                     getpid());
> +        ret.data.u64 = UINT64_MAX;
> +    } else {
> +        ret.data.u64 = pci_default_read_config(dev, conf->addr, conf->l);

Isn't it endianess issue here? It might makes sense to
declare ConfDataMsg and PCI_CONFIG_READ/PCI_CONFIG_WRITE
packets in little endian.

> +    }
> +
> +    ret.cmd = RET_MSG;
> +    ret.size = sizeof(ret.data.u64);
> +
> +    mpqemu_msg_send(&ret, ioc, &local_err);
> +    if (local_err) {
> +        error_report("Could not send message to proxy from pid %d",
> +                     getpid());
> +    }
> +}
> diff --git a/hw/pci/proxy.c b/hw/pci/proxy.c
> index 7a12f23..27714fe 100644
> --- a/hw/pci/proxy.c
> +++ b/hw/pci/proxy.c
> @@ -16,6 +16,8 @@
>   #include "hw/qdev-properties.h"
>   #include "monitor/monitor.h"
>   #include "migration/blocker.h"
> +#include "io/mpqemu-link.h"
> +#include "qemu/error-report.h"
>   
>   static void proxy_set_socket(PCIProxyDev *pdev, int fd, Error **errp)
>   {
> @@ -69,6 +71,51 @@ static void pci_proxy_dev_exit(PCIDevice *pdev)
>       error_free(dev->migration_blocker);
>   }
>   
> +static int config_op_send(PCIProxyDev *pdev, uint32_t addr, uint32_t *val,
> +                          int l, unsigned int op)
> +{
> +    MPQemuMsg msg = { 0 };
> +    uint64_t ret = -EINVAL;
> +    Error *local_err = NULL;
> +
> +    msg.cmd = op;
> +    msg.data.conf_data.addr = addr;
> +    msg.data.conf_data.val = (op == PCI_CONFIG_WRITE) ? *val : 0;
> +    msg.data.conf_data.l = l;
> +    msg.size = sizeof(ConfDataMsg);
> +
> +    ret = mpqemu_msg_send_and_await_reply(&msg, pdev, &local_err);
> +    if (local_err) {
> +        error_report_err(local_err);
> +    }
> +    if (op == PCI_CONFIG_READ) {
> +        *val = (uint32_t)ret;
> +    }
> +
> +    return ret;
> +}
> +
> +static uint32_t pci_proxy_read_config(PCIDevice *d, uint32_t addr, int len)
> +{
> +    uint32_t val;
> +
> +    (void)config_op_send(PCI_PROXY_DEV(d), addr, &val, len, PCI_CONFIG_READ);
> +
> +    return val;
> +}
> +
> +static void pci_proxy_write_config(PCIDevice *d, uint32_t addr, uint32_t val,
> +                                   int l)
> +{
> +    /*
> +     * Some of the functions access the copy of the remote device
> +     * PCI config space, therefore maintain it updated.
> +     */
> +    pci_default_write_config(d, addr, val, l);
> +
> +    (void)config_op_send(PCI_PROXY_DEV(d), addr, &val, l, PCI_CONFIG_WRITE);
> +}
> +
>   static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(klass);
> @@ -76,6 +123,9 @@ static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
>   
>       k->realize = pci_proxy_dev_realize;
>       k->exit = pci_proxy_dev_exit;
> +    k->config_read = pci_proxy_read_config;
> +    k->config_write = pci_proxy_write_config;
> +
>       device_class_set_props(dc, proxy_properties);
>   }
>   
> diff --git a/include/io/mpqemu-link.h b/include/io/mpqemu-link.h
> index 4bea5da..459d345 100644
> --- a/include/io/mpqemu-link.h
> +++ b/include/io/mpqemu-link.h
> @@ -34,6 +34,8 @@ typedef enum {
>       MPQEMU_CMD_INIT,
>       SYNC_SYSMEM,
>       RET_MSG,
> +    PCI_CONFIG_WRITE,
> +    PCI_CONFIG_READ,
>       MPQEMU_CMD_MAX,
>   } MPQemuCmd;
>   
> @@ -43,6 +45,12 @@ typedef struct {
>       off_t offsets[REMOTE_MAX_FDS];
>   } SyncSysmemMsg;
>   
> +typedef struct {
> +    uint32_t addr;
> +    uint32_t val;
> +    int l;
> +} ConfDataMsg;

Maybe name this PciConfDataMsg?

> +
>   /**
>    * MPQemuMsg:
>    * @cmd: The remote command
> @@ -60,6 +68,7 @@ typedef struct {
>   
>       union {
>           uint64_t u64;
> +        ConfDataMsg conf_data;
>           SyncSysmemMsg sync_sysmem;
>       } data;
>   
> diff --git a/io/mpqemu-link.c b/io/mpqemu-link.c
> index 1339cc7..5ef82da 100644
> --- a/io/mpqemu-link.c
> +++ b/io/mpqemu-link.c
> @@ -278,6 +278,12 @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
>               return false;
>           }
>           break;
> +    case PCI_CONFIG_WRITE:
> +    case PCI_CONFIG_READ:
> +        if (msg->size != sizeof(ConfDataMsg)) {
> +            return false;
> +        }
> +        break;
>       default:
>           break;
>       }
>
Philippe Mathieu-Daudé Oct. 23, 2020, 5:20 p.m. UTC | #2 
On 10/23/20 6:59 PM, Philippe Mathieu-Daudé wrote:
> On 10/15/20 8:05 PM, Jagannathan Raman wrote:
>> From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
>>
>> The Proxy Object sends the PCI config space accesses as messages
>> to the remote process over the communication channel
...

>> +static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
>> +                                MPQemuMsg *msg)
>> +{
>> +    ConfDataMsg *conf = (ConfDataMsg *)&msg->data.conf_data;
>> +    MPQemuMsg ret = { 0 };
>> +    Error *local_err = NULL;
>> +
>> +    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
>> +        error_report("Bad address received when reading PCI config, 
>> pid %d",
>> +                     getpid());
>> +        ret.data.u64 = UINT64_MAX;
>> +    } else {
>> +        ret.data.u64 = pci_default_read_config(dev, conf->addr, 
>> conf->l);
> 
> Isn't it endianess issue here? It might makes sense to
> declare ConfDataMsg and PCI_CONFIG_READ/PCI_CONFIG_WRITE
> packets in little endian.

Bah Stefan told me to look at the specs which are included in
the latest patch (docs/multi-process.rst). As I process patches
of this series in order I haven't looked at it yet. Still,
why not put it first in your series?

Regards,

Phil.
diff mbox series

Patch

diff --git a/hw/i386/remote-msg.c b/hw/i386/remote-msg.c
index 6451b77..94937db 100644
--- a/hw/i386/remote-msg.c
+++ b/hw/i386/remote-msg.c
@@ -15,6 +15,12 @@ 
 #include "io/mpqemu-link.h"
 #include "qapi/error.h"
 #include "sysemu/runstate.h"
+#include "hw/pci/pci.h"
+
+static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
+                                 MPQemuMsg *msg);
+static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
+                                MPQemuMsg *msg);
 
 void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
 {
@@ -43,6 +49,12 @@  void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         }
 
         switch (msg.cmd) {
+        case PCI_CONFIG_WRITE:
+            process_config_write(com->ioc, pci_dev, &msg);
+            break;
+        case PCI_CONFIG_READ:
+            process_config_read(com->ioc, pci_dev, &msg);
+            break;
         default:
             error_setg(&local_err,
                        "Unknown command (%d) received for device %s (pid=%d)",
@@ -60,3 +72,53 @@  void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
 
     return;
 }
+
+static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
+                                 MPQemuMsg *msg)
+{
+    ConfDataMsg *conf = (ConfDataMsg *)&msg->data.conf_data;
+    MPQemuMsg ret = { 0 };
+    Error *local_err = NULL;
+
+    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
+        error_report("Bad address received when writing PCI config, pid %d",
+                     getpid());
+        ret.data.u64 = UINT64_MAX;
+    } else {
+        pci_default_write_config(dev, conf->addr, conf->val, conf->l);
+    }
+
+    ret.cmd = RET_MSG;
+    ret.size = sizeof(ret.data.u64);
+
+    mpqemu_msg_send(&ret, ioc, &local_err);
+    if (local_err) {
+        error_report("Could not send message to proxy from pid %d",
+                     getpid());
+    }
+}
+
+static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
+                                MPQemuMsg *msg)
+{
+    ConfDataMsg *conf = (ConfDataMsg *)&msg->data.conf_data;
+    MPQemuMsg ret = { 0 };
+    Error *local_err = NULL;
+
+    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
+        error_report("Bad address received when reading PCI config, pid %d",
+                     getpid());
+        ret.data.u64 = UINT64_MAX;
+    } else {
+        ret.data.u64 = pci_default_read_config(dev, conf->addr, conf->l);
+    }
+
+    ret.cmd = RET_MSG;
+    ret.size = sizeof(ret.data.u64);
+
+    mpqemu_msg_send(&ret, ioc, &local_err);
+    if (local_err) {
+        error_report("Could not send message to proxy from pid %d",
+                     getpid());
+    }
+}
diff --git a/hw/pci/proxy.c b/hw/pci/proxy.c
index 7a12f23..27714fe 100644
--- a/hw/pci/proxy.c
+++ b/hw/pci/proxy.c
@@ -16,6 +16,8 @@ 
 #include "hw/qdev-properties.h"
 #include "monitor/monitor.h"
 #include "migration/blocker.h"
+#include "io/mpqemu-link.h"
+#include "qemu/error-report.h"
 
 static void proxy_set_socket(PCIProxyDev *pdev, int fd, Error **errp)
 {
@@ -69,6 +71,51 @@  static void pci_proxy_dev_exit(PCIDevice *pdev)
     error_free(dev->migration_blocker);
 }
 
+static int config_op_send(PCIProxyDev *pdev, uint32_t addr, uint32_t *val,
+                          int l, unsigned int op)
+{
+    MPQemuMsg msg = { 0 };
+    uint64_t ret = -EINVAL;
+    Error *local_err = NULL;
+
+    msg.cmd = op;
+    msg.data.conf_data.addr = addr;
+    msg.data.conf_data.val = (op == PCI_CONFIG_WRITE) ? *val : 0;
+    msg.data.conf_data.l = l;
+    msg.size = sizeof(ConfDataMsg);
+
+    ret = mpqemu_msg_send_and_await_reply(&msg, pdev, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+    if (op == PCI_CONFIG_READ) {
+        *val = (uint32_t)ret;
+    }
+
+    return ret;
+}
+
+static uint32_t pci_proxy_read_config(PCIDevice *d, uint32_t addr, int len)
+{
+    uint32_t val;
+
+    (void)config_op_send(PCI_PROXY_DEV(d), addr, &val, len, PCI_CONFIG_READ);
+
+    return val;
+}
+
+static void pci_proxy_write_config(PCIDevice *d, uint32_t addr, uint32_t val,
+                                   int l)
+{
+    /*
+     * Some of the functions access the copy of the remote device
+     * PCI config space, therefore maintain it updated.
+     */
+    pci_default_write_config(d, addr, val, l);
+
+    (void)config_op_send(PCI_PROXY_DEV(d), addr, &val, l, PCI_CONFIG_WRITE);
+}
+
 static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -76,6 +123,9 @@  static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
 
     k->realize = pci_proxy_dev_realize;
     k->exit = pci_proxy_dev_exit;
+    k->config_read = pci_proxy_read_config;
+    k->config_write = pci_proxy_write_config;
+
     device_class_set_props(dc, proxy_properties);
 }
 
diff --git a/include/io/mpqemu-link.h b/include/io/mpqemu-link.h
index 4bea5da..459d345 100644
--- a/include/io/mpqemu-link.h
+++ b/include/io/mpqemu-link.h
@@ -34,6 +34,8 @@  typedef enum {
     MPQEMU_CMD_INIT,
     SYNC_SYSMEM,
     RET_MSG,
+    PCI_CONFIG_WRITE,
+    PCI_CONFIG_READ,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
@@ -43,6 +45,12 @@  typedef struct {
     off_t offsets[REMOTE_MAX_FDS];
 } SyncSysmemMsg;
 
+typedef struct {
+    uint32_t addr;
+    uint32_t val;
+    int l;
+} ConfDataMsg;
+
 /**
  * MPQemuMsg:
  * @cmd: The remote command
@@ -60,6 +68,7 @@  typedef struct {
 
     union {
         uint64_t u64;
+        ConfDataMsg conf_data;
         SyncSysmemMsg sync_sysmem;
     } data;
 
diff --git a/io/mpqemu-link.c b/io/mpqemu-link.c
index 1339cc7..5ef82da 100644
--- a/io/mpqemu-link.c
+++ b/io/mpqemu-link.c
@@ -278,6 +278,12 @@  bool mpqemu_msg_valid(MPQemuMsg *msg)
             return false;
         }
         break;
+    case PCI_CONFIG_WRITE:
+    case PCI_CONFIG_READ:
+        if (msg->size != sizeof(ConfDataMsg)) {
+            return false;
+        }
+        break;
     default:
         break;
     }