[Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

[Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

[Paul Durrant]

This series modifies QEMU to use the new guest resource mapping API
(available in Xen 4.11+) to map ioreq pages.

Paul Durrant (2):
  xen-hvm: create separate function for ioreq server initialization
  xen-hvm: try to use xenforeignmemory_map_resource() to map ioreq pages

 configure                   |   5 ++
 hw/i386/xen/trace-events    |   1 +
 hw/i386/xen/xen-hvm.c       | 114 ++++++++++++++++++++++++++++++++------------
 include/hw/xen/xen_common.h |  14 ++++++
 4 files changed, 104 insertions(+), 30 deletions(-)

-- 
2.11.0

[Qemu-devel] [PATCH 1/2] xen-hvm: create separate function for ioreq server initialization

[Paul Durrant]

The code is sufficiently substantial that it improves code readability
to put it in a new function called by xen_hvm_init() rather than having
it inline.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
---
 hw/i386/xen/xen-hvm.c | 76 +++++++++++++++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 30 deletions(-)

diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
index caa563be3d..6ffa3c22cc 100644
--- a/hw/i386/xen/xen-hvm.c
+++ b/hw/i386/xen/xen-hvm.c
@@ -95,7 +95,8 @@ typedef struct XenIOState {
     CPUState **cpu_by_vcpu_id;
     /* the evtchn port for polling the notification, */
     evtchn_port_t *ioreq_local_port;
-    /* evtchn local port for buffered io */
+    /* evtchn remote and local ports for buffered io */
+    evtchn_port_t bufioreq_remote_port;
     evtchn_port_t bufioreq_local_port;
     /* the evtchn fd for polling */
     xenevtchn_handle *xce_handle;
@@ -1236,12 +1237,52 @@ static void xen_wakeup_notifier(Notifier *notifier, void *data)
     xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
 }
 
-void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
+static int xen_map_ioreq_server(XenIOState *state)
 {
-    int i, rc;
     xen_pfn_t ioreq_pfn;
     xen_pfn_t bufioreq_pfn;
     evtchn_port_t bufioreq_evtchn;
+    int rc;
+
+    rc = xen_get_ioreq_server_info(xen_domid, state->ioservid,
+                                   &ioreq_pfn, &bufioreq_pfn,
+                                   &bufioreq_evtchn);
+    if (rc < 0) {
+        error_report("failed to get ioreq server info: error %d handle=%p",
+                     errno, xen_xc);
+        return rc;
+    }
+
+    DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
+    DPRINTF("buffered io page at pfn %lx\n", bufioreq_pfn);
+    DPRINTF("buffered io evtchn is %x\n", bufioreq_evtchn);
+
+    state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
+                                              PROT_READ | PROT_WRITE,
+                                              1, &ioreq_pfn, NULL);
+    if (state->shared_page == NULL) {
+        error_report("map shared IO page returned error %d handle=%p",
+                     errno, xen_xc);
+        return -1;
+    }
+
+    state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
+                                                   PROT_READ | PROT_WRITE,
+                                                   1, &bufioreq_pfn, NULL);
+    if (state->buffered_io_page == NULL) {
+        error_report("map buffered IO page returned error %d", errno);
+        return -1;
+    }
+
+    state->bufioreq_remote_port = bufioreq_evtchn;
+
+    return 0;
+}
+
+void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
+{
+    int i, rc;
+    xen_pfn_t ioreq_pfn;
     XenIOState *state;
 
     state = g_malloc0(sizeof (XenIOState));
@@ -1269,25 +1310,8 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
     state->wakeup.notify = xen_wakeup_notifier;
     qemu_register_wakeup_notifier(&state->wakeup);
 
-    rc = xen_get_ioreq_server_info(xen_domid, state->ioservid,
-                                   &ioreq_pfn, &bufioreq_pfn,
-                                   &bufioreq_evtchn);
+    rc = xen_map_ioreq_server(state);
     if (rc < 0) {
-        error_report("failed to get ioreq server info: error %d handle=%p",
-                     errno, xen_xc);
-        goto err;
-    }
-
-    DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
-    DPRINTF("buffered io page at pfn %lx\n", bufioreq_pfn);
-    DPRINTF("buffered io evtchn is %x\n", bufioreq_evtchn);
-
-    state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
-                                              PROT_READ|PROT_WRITE,
-                                              1, &ioreq_pfn, NULL);
-    if (state->shared_page == NULL) {
-        error_report("map shared IO page returned error %d handle=%p",
-                     errno, xen_xc);
         goto err;
     }
 
@@ -1308,14 +1332,6 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
         goto err;
     }
 
-    state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
-                                                   PROT_READ|PROT_WRITE,
-                                                   1, &bufioreq_pfn, NULL);
-    if (state->buffered_io_page == NULL) {
-        error_report("map buffered IO page returned error %d", errno);
-        goto err;
-    }
-
     /* Note: cpus is empty at this point in init */
     state->cpu_by_vcpu_id = g_malloc0(max_cpus * sizeof(CPUState *));
 
@@ -1340,7 +1356,7 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
     }
 
     rc = xenevtchn_bind_interdomain(state->xce_handle, xen_domid,
-                                    bufioreq_evtchn);
+                                    state->bufioreq_remote_port);
     if (rc == -1) {
         error_report("buffered evtchn bind error %d", errno);
         goto err;
-- 
2.11.0

[Qemu-devel] [PATCH 2/2] xen-hvm: try to use xenforeignmemory_map_resource() to map ioreq pages

[Paul Durrant]

Xen 4.11 has a new API to directly map guest resources. Among the resources
that can be mapped using this API are ioreq pages.

This patch modifies QEMU to attempt to use the new API should it exist,
falling back to the previous mechanism if it is unavailable.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
---
 configure                   |  5 ++++
 hw/i386/xen/trace-events    |  1 +
 hw/i386/xen/xen-hvm.c       | 68 +++++++++++++++++++++++++++++++++++----------
 include/hw/xen/xen_common.h | 14 ++++++++++
 4 files changed, 73 insertions(+), 15 deletions(-)

diff --git a/configure b/configure
index 1443422e83..0f9c2f000e 100755
--- a/configure
+++ b/configure
@@ -2229,12 +2229,17 @@ EOF
 #undef XC_WANT_COMPAT_DEVICEMODEL_API
 #define __XEN_TOOLS__
 #include <xendevicemodel.h>
+#include <xenforeignmemory.h>
 int main(void) {
   xendevicemodel_handle *xd;
+  xenforeignmemory_handle *xfmem;
 
   xd = xendevicemodel_open(0, 0);
   xendevicemodel_pin_memory_cacheattr(xd, 0, 0, 0, 0);
 
+  xfmem = xenforeignmemory_open(0, 0);
+  xenforeignmemory_map_resource(xfmem, 0, 0, 0, 0, 0, NULL, 0, 0);
+
   return 0;
 }
 EOF
diff --git a/hw/i386/xen/trace-events b/hw/i386/xen/trace-events
index 8dab7bcfe0..38616b698f 100644
--- a/hw/i386/xen/trace-events
+++ b/hw/i386/xen/trace-events
@@ -15,6 +15,7 @@ cpu_ioreq_pio(void *req, uint32_t dir, uint32_t df, uint32_t data_is_ptr, uint64
 cpu_ioreq_pio_read_reg(void *req, uint64_t data, uint64_t addr, uint32_t size) "I/O=%p pio read reg data=0x%"PRIx64" port=0x%"PRIx64" size=%d"
 cpu_ioreq_pio_write_reg(void *req, uint64_t data, uint64_t addr, uint32_t size) "I/O=%p pio write reg data=0x%"PRIx64" port=0x%"PRIx64" size=%d"
 cpu_ioreq_move(void *req, uint32_t dir, uint32_t df, uint32_t data_is_ptr, uint64_t addr, uint64_t data, uint32_t count, uint32_t size) "I/O=%p copy dir=%d df=%d ptr=%d port=0x%"PRIx64" data=0x%"PRIx64" count=%d size=%d"
+xen_map_resource_ioreq(uint32_t id, void *addr) "id: %u addr: %p"
 
 # xen-mapcache.c
 xen_map_cache(uint64_t phys_addr) "want 0x%"PRIx64
diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
index 6ffa3c22cc..664cc52532 100644
--- a/hw/i386/xen/xen-hvm.c
+++ b/hw/i386/xen/xen-hvm.c
@@ -1239,13 +1239,41 @@ static void xen_wakeup_notifier(Notifier *notifier, void *data)
 
 static int xen_map_ioreq_server(XenIOState *state)
 {
+    void *addr = NULL;
+    xenforeignmemory_resource_handle *fres;
     xen_pfn_t ioreq_pfn;
     xen_pfn_t bufioreq_pfn;
     evtchn_port_t bufioreq_evtchn;
     int rc;
 
+    /*
+     * Attempt to map using the resource API and fall back to normal
+     * foreign mapping if this is not supported.
+     */
+    QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_bufioreq != 0);
+    QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_ioreq(0) != 1);
+    fres = xenforeignmemory_map_resource(xen_fmem, xen_domid,
+                                         XENMEM_resource_ioreq_server,
+                                         state->ioservid, 0, 2,
+                                         &addr,
+                                         PROT_READ | PROT_WRITE, 0);
+    if (fres != NULL) {
+        trace_xen_map_resource_ioreq(state->ioservid, addr);
+        state->buffered_io_page = addr;
+        state->shared_page = addr + TARGET_PAGE_SIZE;
+    } else {
+        error_report("failed to map ioreq server resources: error %d handle=%p",
+                     errno, xen_xc);
+        if (errno != EOPNOTSUPP) {
+            return -1;
+        }
+    }
+
     rc = xen_get_ioreq_server_info(xen_domid, state->ioservid,
-                                   &ioreq_pfn, &bufioreq_pfn,
+                                   (state->shared_page == NULL) ?
+                                   &ioreq_pfn : NULL,
+                                   (state->buffered_io_page == NULL) ?
+                                   &bufioreq_pfn : NULL,
                                    &bufioreq_evtchn);
     if (rc < 0) {
         error_report("failed to get ioreq server info: error %d handle=%p",
@@ -1253,27 +1281,37 @@ static int xen_map_ioreq_server(XenIOState *state)
         return rc;
     }
 
-    DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
-    DPRINTF("buffered io page at pfn %lx\n", bufioreq_pfn);
-    DPRINTF("buffered io evtchn is %x\n", bufioreq_evtchn);
-
-    state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
-                                              PROT_READ | PROT_WRITE,
-                                              1, &ioreq_pfn, NULL);
     if (state->shared_page == NULL) {
-        error_report("map shared IO page returned error %d handle=%p",
-                     errno, xen_xc);
-        return -1;
+        DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
+
+        state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
+                                                  PROT_READ | PROT_WRITE,
+                                                  1, &ioreq_pfn, NULL);
+        if (state->shared_page == NULL) {
+            error_report("map shared IO page returned error %d handle=%p",
+                         errno, xen_xc);
+        }
     }
 
-    state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
-                                                   PROT_READ | PROT_WRITE,
-                                                   1, &bufioreq_pfn, NULL);
     if (state->buffered_io_page == NULL) {
-        error_report("map buffered IO page returned error %d", errno);
+        DPRINTF("buffered io page at pfn %lx\n", bufioreq_pfn);
+
+        state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
+                                                       PROT_READ | PROT_WRITE,
+                                                       1, &bufioreq_pfn,
+                                                       NULL);
+        if (state->buffered_io_page == NULL) {
+            error_report("map buffered IO page returned error %d", errno);
+            return -1;
+        }
+    }
+
+    if (state->shared_page == NULL || state->buffered_io_page == NULL) {
         return -1;
     }
 
+    DPRINTF("buffered io evtchn is %x\n", bufioreq_evtchn);
+
     state->bufioreq_remote_port = bufioreq_evtchn;
 
     return 0;
diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h
index 5f1402b494..d925751040 100644
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -119,6 +119,20 @@ static inline int xendevicemodel_pin_memory_cacheattr(
     return xc_domain_pin_memory_cacheattr(xen_xc, domid, start, end, type);
 }
 
+typedef void xenforeignmemory_resource_handle;
+
+#define XENMEM_resource_ioreq_server_frame_bufioreq 0
+#define XENMEM_resource_ioreq_server_frame_ioreq(n) (1 + (n))
+
+static inline xenforeignmemory_resource_handle *xenforeignmemory_map_resource(
+    xenforeignmemory_handle *fmem, domid_t domid, unsigned int type,
+    unsigned int id, unsigned long frame, unsigned long nr_frames,
+    void **paddr, int prot, int flags)
+{
+    errno = EOPNOTSUPP;
+    return -1;
+}
+
 #endif /* CONFIG_XEN_CTRL_INTERFACE_VERSION < 41100 */
 
 #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 41000
-- 
2.11.0

Re: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

[no-reply]

Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20180509154604.25530-1-paul.durrant@citrix.com
Subject: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

=== TEST SCRIPT BEGIN ===
#!/bin/bash

BASE=base
n=1
total=$(git log --oneline $BASE.. | wc -l)
failed=0

git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram

commits="$(git log --format=%H --reverse $BASE..)"
for c in $commits; do
    echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..."
    if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
        failed=1
        echo
    fi
    n=$((n+1))
done

exit $failed
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 * [new tag]               patchew/20180509154604.25530-1-paul.durrant@citrix.com -> patchew/20180509154604.25530-1-paul.durrant@citrix.com
 * [new tag]               patchew/20180509154849.27979-1-richard.henderson@linaro.org -> patchew/20180509154849.27979-1-richard.henderson@linaro.org
 * [new tag]               patchew/20180509154949.8206-1-mreitz@redhat.com -> patchew/20180509154949.8206-1-mreitz@redhat.com
Switched to a new branch 'test'
16691ff49e xen-hvm: try to use xenforeignmemory_map_resource() to map ioreq pages
d4bcd68252 xen-hvm: create separate function for ioreq server initialization

=== OUTPUT BEGIN ===
Checking PATCH 1/2: xen-hvm: create separate function for ioreq server initialization...
Checking PATCH 2/2: xen-hvm: try to use xenforeignmemory_map_resource() to map ioreq pages...
ERROR: spaces required around that '*' (ctx:WxV)
#164: FILE: include/hw/xen/xen_common.h:128:
+    xenforeignmemory_handle *fmem, domid_t domid, unsigned int type,
                             ^

total: 1 errors, 0 warnings, 138 lines checked

Your patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

=== OUTPUT END ===

Test command exited with code: 1


---
Email generated automatically by Patchew [http://patchew.org/].
Please send your feedback to patchew-devel@redhat.com

Re: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

[Paul Durrant]

> -----Original Message-----
> From: no-reply@patchew.org [mailto:no-reply@patchew.org]
> Sent: 09 May 2018 17:02
> To: Paul Durrant <Paul.Durrant@citrix.com>
> Cc: famz@redhat.com; qemu-devel@nongnu.org; xen-
> devel@lists.xenproject.org; Paul Durrant <Paul.Durrant@citrix.com>
> Subject: Re: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping
> API
> 
> Hi,
> 
> This series seems to have some coding style problems. See output below for
> more information:
> 
> Type: series
> Message-id: 20180509154604.25530-1-paul.durrant@citrix.com
> Subject: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping
> API
> 
> === TEST SCRIPT BEGIN ===
> #!/bin/bash
> 
> BASE=base
> n=1
> total=$(git log --oneline $BASE.. | wc -l)
> failed=0
> 
> git config --local diff.renamelimit 0
> git config --local diff.renames True
> git config --local diff.algorithm histogram
> 
> commits="$(git log --format=%H --reverse $BASE..)"
> for c in $commits; do
>     echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..."
>     if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then
>         failed=1
>         echo
>     fi
>     n=$((n+1))
> done
> 
> exit $failed
> === TEST SCRIPT END ===
> 
> Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
> From https://github.com/patchew-project/qemu
>  * [new tag]               patchew/20180509154604.25530-1-
> paul.durrant@citrix.com -> patchew/20180509154604.25530-1-
> paul.durrant@citrix.com
>  * [new tag]               patchew/20180509154849.27979-1-
> richard.henderson@linaro.org -> patchew/20180509154849.27979-1-
> richard.henderson@linaro.org
>  * [new tag]               patchew/20180509154949.8206-1-mreitz@redhat.com ->
> patchew/20180509154949.8206-1-mreitz@redhat.com
> Switched to a new branch 'test'
> 16691ff49e xen-hvm: try to use xenforeignmemory_map_resource() to map
> ioreq pages
> d4bcd68252 xen-hvm: create separate function for ioreq server initialization
> 
> === OUTPUT BEGIN ===
> Checking PATCH 1/2: xen-hvm: create separate function for ioreq server
> initialization...
> Checking PATCH 2/2: xen-hvm: try to use
> xenforeignmemory_map_resource() to map ioreq pages...
> ERROR: spaces required around that '*' (ctx:WxV)
> #164: FILE: include/hw/xen/xen_common.h:128:
> +    xenforeignmemory_handle *fmem, domid_t domid, unsigned int type,
>                              ^
> 
> total: 1 errors, 0 warnings, 138 lines checked
> 
> Your patch has style problems, please review.  If any of these errors
> are false positives report them to the maintainer, see
> CHECKPATCH in MAINTAINERS.

This style warning appears to be spurious.

  Paul

> 
> === OUTPUT END ===
> 
> Test command exited with code: 1
> 
> 
> ---
> Email generated automatically by Patchew [http://patchew.org/].
> Please send your feedback to patchew-devel@redhat.com

Re: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

[Eric Blake]

On 05/09/2018 11:05 AM, Paul Durrant wrote:

>> xenforeignmemory_map_resource() to map ioreq pages...
>> ERROR: spaces required around that '*' (ctx:WxV)
>> #164: FILE: include/hw/xen/xen_common.h:128:
>> +    xenforeignmemory_handle *fmem, domid_t domid, unsigned int type,
>>                               ^
>>
>> total: 1 errors, 0 warnings, 138 lines checked
>>
>> Your patch has style problems, please review.  If any of these errors
>> are false positives report them to the maintainer, see
>> CHECKPATCH in MAINTAINERS.
> 
> This style warning appears to be spurious.

Yep, and it's because xenforeignmemory_handle doesn't follow our usual 
conventions for a type name.  See commit 5ac067a if you want to add it 
to the list of whitelisted exception type names, to silence messages 
like this.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping API

[Paul Durrant]

> -----Original Message-----
> From: Eric Blake [mailto:eblake@redhat.com]
> Sent: 09 May 2018 18:26
> To: Paul Durrant <Paul.Durrant@citrix.com>; qemu-devel@nongnu.org
> Cc: xen-devel@lists.xenproject.org; famz@redhat.com
> Subject: Re: [Qemu-devel] [PATCH 0/2] xen-hvm: use new resource mapping
> API
> 
> On 05/09/2018 11:05 AM, Paul Durrant wrote:
> 
> >> xenforeignmemory_map_resource() to map ioreq pages...
> >> ERROR: spaces required around that '*' (ctx:WxV)
> >> #164: FILE: include/hw/xen/xen_common.h:128:
> >> +    xenforeignmemory_handle *fmem, domid_t domid, unsigned int
> type,
> >>                               ^
> >>
> >> total: 1 errors, 0 warnings, 138 lines checked
> >>
> >> Your patch has style problems, please review.  If any of these errors
> >> are false positives report them to the maintainer, see
> >> CHECKPATCH in MAINTAINERS.
> >
> > This style warning appears to be spurious.
> 
> Yep, and it's because xenforeignmemory_handle doesn't follow our usual
> conventions for a type name.  See commit 5ac067a if you want to add it
> to the list of whitelisted exception type names, to silence messages
> like this.

Thanks Eric. I'll send a v2 series with a suitable additional patch.

  Cheers,

    Paul

> 
> --
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.           +1-919-301-3266
> Virtualization:  qemu.org | libvirt.org