On Wed, Sep 17, 2014 at 05:54:28PM +0200, Jan Kiszka wrote: > On 2014-08-21 19:44, John Snow wrote: > > In the Intel ICH9 data sheet, the MSI capability offset > > in the PCI configuration space for ICH9 AHCI devices is > > specified to be 0x80. > > > > Further, the PCI capability pointer should always point > > to 0x80 in ICH9 devices, despite the fact that AHCI 1.3 > > specifies that it should be pointing to PMCAP (Which in > > this instance would be 0x70) to maintain adherence to > > the Intel data sheet specifications and real observed behavior. > > > > Signed-off-by: John Snow <js...@redhat.com> > > --- > > hw/ide/ich.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/hw/ide/ich.c b/hw/ide/ich.c > > index a2f1639..8eb77a1 100644 > > --- a/hw/ide/ich.c > > +++ b/hw/ide/ich.c > > @@ -71,6 +71,7 @@ > > #include <hw/ide/pci.h> > > #include <hw/ide/ahci.h> > > > > +#define ICH9_MSI_CAP_OFFSET 0x80 > > #define ICH9_SATA_CAP_OFFSET 0xA8 > > > > #define ICH9_IDP_BAR 4 > > @@ -115,7 +116,6 @@ static int pci_ich9_ahci_init(PCIDevice *dev) > > /* XXX Software should program this register */ > > dev->config[0x90] = 1 << 6; /* Address Map Register - AHCI mode */ > > > > - msi_init(dev, 0x50, 1, true, false); > > d->ahci.irq = pci_allocate_irq(dev); > > > > pci_register_bar(dev, ICH9_IDP_BAR, PCI_BASE_ADDRESS_SPACE_IO, > > @@ -135,6 +135,11 @@ static int pci_ich9_ahci_init(PCIDevice *dev) > > (ICH9_IDP_BAR + 0x4) | (ICH9_IDP_INDEX_LOG2 << 4)); > > d->ahci.idp_offset = ICH9_IDP_INDEX; > > > > + /* Although the AHCI 1.3 specification states that the first capability > > + * should be PMCAP, the Intel ICH9 data sheet specifies that the ICH9 > > + * AHCI device puts the MSI capability first, pointing to 0x80. */ > > + msi_init(dev, ICH9_MSI_CAP_OFFSET, 1, true, false); > > + > > return 0; > > } > > > > > > I did this for HDA recently, and it became clear that this requires a > compat switch to expose the old, broken layout to older guests. > Otherwise you can't migrate from them. > > Jan
Absolutely but ahci still disables migration :) > -- > Siemens AG, Corporate Technology, CT RTC ITP SES-DE > Corporate Competence Center Embedded Linux
