xen-hvm: try to use xenforeignmemory_map_resource() to map ioreq pages

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>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/configure b/configure
index a6a4616c3ee571729757db18dc4a09d0872963e7..be6edc7b81346a566432d8e247deb22a575b4d4d 100755 (executable)
--- a/configure
+++ b/configure
@@ -2231,12 +2231,17 @@ 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 8dab7bcfe0544cc024a13043042cb5c6053da99b..38616b698f7cf88876c1e3ed4c7f058d152a8f6e 100644 (file)
--- 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 2afab6573be6dce6c98da4596f42e8248e6f0650..54f99abfea0b6dcb8e14b9094917da9e3a622f24 100644 (file)
--- a/hw/i386/xen/xen-hvm.c
+++ b/hw/i386/xen/xen-hvm.c
@@ -1237,13 +1237,39 @@ 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 if (errno != EOPNOTSUPP) {
+        error_report("failed to map ioreq server resources: error %d handle=%p",
+                     errno, xen_xc);
+        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",
@@ -1251,27 +1277,37 @@ 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 bbf207dcef6b2095a7a34ddc86085f45a87f4411..93f631e5bf0ee5b64fbd980c433ba9bdd82b94ac 100644 (file)
--- a/include/hw/xen/xen_common.h
+++ b/include/hw/xen/xen_common.h
@@ -119,6 +119,22 @@ 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 0
+
+#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 NULL;
+}
+
 #endif /* CONFIG_XEN_CTRL_INTERFACE_VERSION < 41100 */
 
 #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 41000