On Sun, 1 Dec 2024 22:11:29 -0700 Alex Williamson <alex.william...@redhat.com> wrote:
> On Mon, 2 Dec 2024 00:09:31 +0800 > Tomita Moeko <tomitamo...@gmail.com> wrote: > > > Both intel documentation [1][2] and i915 driver shows GGMS represents > > GTT stolen memory size in multiple of 1MB, not 2MB starting from gen 8. > > > > [1] > > https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/3rd-gen-core-desktop-vol-2-datasheet.pdf > > [2] > > https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/4th-gen-core-family-desktop-vol-2-datasheet.pdf > > > > Signed-off-by: Tomita Moeko <tomitamo...@gmail.com> > > --- > > hw/vfio/igd.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c > > index 4047f4f071..e40e601026 100644 > > --- a/hw/vfio/igd.c > > +++ b/hw/vfio/igd.c > > @@ -268,7 +268,7 @@ static int vfio_igd_gtt_max(VFIOPCIDevice *vdev) > > > > gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, sizeof(gmch)); > > ggms = (gmch >> (gen < 8 ? 8 : 6)) & 0x3; > > - if (gen > 6) { > > + if (gen > 7) { > > ggms = 1 << ggms; > > } > > > > @@ -678,7 +678,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int > > nr) > > > > /* Determine the size of stolen memory needed for GTT */ > > ggms_mb = (gmch >> (gen < 8 ? 8 : 6)) & 0x3; > > - if (gen > 6) { > > + if (gen > 7) { > > ggms_mb = 1 << ggms_mb; > > } > > > > I'd argue this should be rolled into patch 4. It's not really fixing > anything because igd_gen() can't return anything between 6 and 8. This > only allows for several device versions that we currently consider to > be gen 6 to align with i915 kernel driver generation by calling them > generation 7. We'd previously lumped them into generation 6 because > there's no functional difference we care about here between 6 & 7. > > In the next patch you replace this '1 << ggms_mb' with '*= 2', which > would be equivalent to 'ggms_mb << 1' and matches your description that > the increment is doubled. Is there a separate bug fix that needs to be > pulled out here? > > Also, please send a cover letter for any series longer than a single > patch and please configure your tools to thread the series. Thanks, Disregard this latter comment, I just wasn't copied on the cover letter and didn't have it in my inbox to root the thread. Thanks, Alex
