Re: [Qemu-devel] AHCI broken in current git, bisected.

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, May 15, 2011 at 07:58:23PM +0400, Alexey Zaytsev wrote:
> Hi.
> 
> The commit 667bb59d2358daeef179583c944becba3f1f9680
> Author: Avi Kivity <avi@redhat.com>
> Date:   Mon Apr 4 18:28:02 2011 +0300
> 
>     ich/ahci: convert to pci_register_bar_simple()
> 
>     Signed-off-by: Avi Kivity <avi@redhat.com>
>     Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> 
> breaks AHCI to the point the disks are not detected by both seabios and Linux:
> 
> [    8.582220] ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xc000 irq 14
> [    8.582646] ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xc008 irq 15
> [    8.603979] ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 10
> [    8.605151] ahci 0000:00:04.0: PCI INT A -> Link[LNKD] -> GSI 10
> (level, high) -> IRQ 10
> [    9.608243] ahci 0000:00:04.0: controller reset failed (0xf000ff53)
> [    9.609948] ahci 0000:00:04.0: PCI INT A disabled
> [    9.610267] ahci: probe of 0000:00:04.0 failed with error -5

Sure enough,

    /* XXX BAR size should be 1k, but that breaks, so bump it to 4k for now */
    pci_register_bar_simple(&d->card, 5, 0x1000, 0, d->ahci.mem);
    msi_init(dev, 0x50, 1, true, false);
    ahci_init(&d->ahci, &dev->qdev, 6);

where ahci_init initializes d->ahci.mem.

Coul;d you try out the following please
(untested, a bit busy now)?

--->

    ich/ahci: fix use of uninitialized memory
    
    The commit 667bb59d2358daeef179583c944becba3f1f9680
    uses d->ahci.mem before it is initialized by
    ahci_init(). Fix this by calling ahci_init() first thing
    so that it's safe to use all fields in the ahci state struct.
    
    Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
    Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/ide/ich.c b/hw/ide/ich.c
index e44339b..5ce0a88 100644
--- a/hw/ide/ich.c
+++ b/hw/ide/ich.c
@@ -77,6 +77,8 @@ static int pci_ich9_ahci_init(PCIDevice *dev)
     struct AHCIPCIState *d;
     d = DO_UPCAST(struct AHCIPCIState, card, dev);
 
+    ahci_init(&d->ahci, &dev->qdev, 6);
+
     pci_config_set_vendor_id(d->card.config, PCI_VENDOR_ID_INTEL);
     pci_config_set_device_id(d->card.config, PCI_DEVICE_ID_INTEL_82801IR);
 
@@ -97,8 +99,6 @@ static int pci_ich9_ahci_init(PCIDevice *dev)
     pci_register_bar_simple(&d->card, 5, 0x1000, 0, d->ahci.mem);
 
     msi_init(dev, 0x50, 1, true, false);
-
-    ahci_init(&d->ahci, &dev->qdev, 6);
     d->ahci.irq = d->card.irq[0];
 
     return 0;

-- 
MST