[Qemu-devel] [PATCH v2] ahci: add -drive support

[Alexander Graf]

We've had support for creating AHCI devices using -device for a while now,
but it's cumbersome to users. We really should provide an easier way for
them to leverage the power of AHCI!

So let's introduce a new if= option to -drive, giving users the same
command line experience as for scsi or ide.

Signed-off-by: Alexander Graf <address@hidden>

---

v1 -> v2:

  - support more than a single drive per adapter
  - support index= option
  - treat IF_AHCI the same as IF_IDE
  - add is_ata() helper to match AHCI || IDE
---
 blockdev.c      |   54 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 blockdev.h      |    7 +++++++
 qemu-options.hx |    7 ++++++-
 vl.c            |    2 ++
 4 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 9e0a72a..744a886 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -32,6 +32,7 @@ static const char *const if_name[IF_COUNT] = {
     [IF_SD] = "sd",
     [IF_VIRTIO] = "virtio",
     [IF_XEN] = "xen",
+    [IF_AHCI] = "ahci",
 };
 
 static const int if_max_devs[IF_COUNT] = {
@@ -51,6 +52,7 @@ static const int if_max_devs[IF_COUNT] = {
      */
     [IF_IDE] = 2,
     [IF_SCSI] = 7,
+    [IF_AHCI] = 6,
 };
 
 /*
@@ -330,15 +332,15 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
     max_devs = if_max_devs[type];
 
     if (cyls || heads || secs) {
-        if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
+        if (cyls < 1 || (is_ata(type) && cyls > 16383)) {
             error_report("invalid physical cyls number");
            return NULL;
        }
-        if (heads < 1 || (type == IF_IDE && heads > 16)) {
+        if (heads < 1 || (is_ata(type) && heads > 16)) {
             error_report("invalid physical heads number");
            return NULL;
        }
-        if (secs < 1 || (type == IF_IDE && secs > 63)) {
+        if (secs < 1 || (is_ata(type) && secs > 63)) {
             error_report("invalid physical secs number");
            return NULL;
        }
@@ -516,7 +518,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
     } else {
         /* no id supplied -> create one */
         dinfo->id = g_malloc0(32);
-        if (type == IF_IDE || type == IF_SCSI)
+        if (is_ata(type) || type == IF_SCSI)
             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
         if (max_devs)
             snprintf(dinfo->id, 32, "%s%i%s%i",
@@ -546,6 +548,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
     case IF_IDE:
     case IF_SCSI:
     case IF_XEN:
+    case IF_AHCI:
     case IF_NONE:
         switch(media) {
        case MEDIA_DISK:
@@ -628,6 +631,49 @@ err:
     return NULL;
 }
 
+static void drive_populate_ahci(void)
+{
+    int bus;
+    QemuOpts *opts;
+
+    for (bus = 0; bus <= drive_get_max_bus(IF_AHCI); bus++) {
+        char devname[] = "ahciXXX";
+        int dev;
+        snprintf(devname, sizeof(devname), "ahci%d", bus);
+
+        /* add ahci host controller */
+        opts = qemu_opts_create(qemu_find_opts("device"), devname, 0, NULL);
+        qemu_opt_set(opts, "driver", "ich9-ahci");
+        for (dev = 0; dev < if_max_devs[IF_AHCI]; dev++) {
+            DriveInfo *dinfo = drive_get(IF_AHCI, bus, dev);
+            char busname[] = "ahciXXX.XXX";
+
+            if (!dinfo) {
+                continue;
+            }
+            snprintf(busname, sizeof(busname), "ahci%d.%d", bus, dev);
+
+            /* attach this ata disk to its bus */
+            opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0, NULL);
+            qemu_opt_set(opts, "driver", "ide-drive");
+            qemu_opt_set(opts, "bus", busname);
+            qemu_opt_set(opts, "drive", dinfo->id);
+        }
+    }
+}
+
+/*
+ * This function creates -device options out of IF_xxx elements,
+ * so that we don't have to mess with user friendly syntax parsing
+ * in device emulation code.
+ *
+ * For now, only AHCI is implemented here.
+ */
+void drive_populate(void)
+{
+    drive_populate_ahci();
+}
+
 void do_commit(Monitor *mon, const QDict *qdict)
 {
     const char *device = qdict_get_str(qdict, "device");
diff --git a/blockdev.h b/blockdev.h
index 260e16b..9d79558 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -23,6 +23,7 @@ typedef enum {
     IF_DEFAULT = -1,            /* for use with drive_add() only */
     IF_NONE,
     IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD, IF_VIRTIO, IF_XEN,
+    IF_AHCI,
     IF_COUNT
 } BlockInterfaceType;
 
@@ -53,6 +54,12 @@ QemuOpts *drive_def(const char *optstr);
 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
                     const char *optstr);
 DriveInfo *drive_init(QemuOpts *arg, int default_to_scsi);
+void drive_populate(void);
+
+static inline bool is_ata(int type)
+{
+    return (type == IF_IDE) || (type == IF_AHCI);
+}
 
 /* device-hotplug */
 
diff --git a/qemu-options.hx b/qemu-options.hx
index 8b66264..9527c51 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -160,7 +160,7 @@ Special files such as iSCSI devices can be specified using 
protocol
 specific URLs. See the section for "Device URL Syntax" for more information.
 @item address@hidden
 This option defines on which type on interface the drive is connected.
-Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio.
+Available types are: ide, scsi, sd, mtd, floppy, pflash, virtio, ahci.
 @item address@hidden,address@hidden
 These options define where is connected the drive by defining the bus number 
and
 the unit id.
@@ -260,6 +260,11 @@ You can connect a SCSI disk with unit ID 6 on the bus #0:
 qemu-system-i386 -drive file=file,if=scsi,bus=0,unit=6
 @end example
 
+You can attach a SATA disk using AHCI:
address@hidden
+qemu-system-i386 -drive file=file,if=ahci
address@hidden example
+
 Instead of @option{-fda}, @option{-fdb}, you can use:
 @example
 qemu-system-i386 -drive file=file,index=0,if=floppy
diff --git a/vl.c b/vl.c
index 1329c30..65410a0 100644
--- a/vl.c
+++ b/vl.c
@@ -3438,6 +3438,8 @@ int main(int argc, char **argv, char **envp)
     default_drive(default_sdcard, snapshot, machine->use_scsi,
                   IF_SD, 0, SD_OPTS);
 
+    drive_populate();
+
     register_savevm_live(NULL, "ram", 0, 4, NULL, ram_save_live, NULL,
                          ram_load, NULL);
 
-- 
1.6.0.2