| Message ID | 20230314013221.124930-1-marmarek@invisiblethingslab.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] IOMMU/VT-d: Fix iommu=no-igfx if the IOMMU scope contains phantom device | expand |
> From: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > Sent: Tuesday, March 14, 2023 9:32 AM > > If the scope for IGD's IOMMU contains additional device that doesn't > actually exist, iommu=no-igfx would not disable that IOMMU. In this > particular case (Thinkpad x230) it included > 00:02.1, but there is no such device on this platform. > Consider only existing devices for "gfx only" check. > > Fixes: 2d7f191b392e ("VT-d: generalize and correct "iommu=no-igfx" > handling") > Signed-off-by: Marek Marczykowski-Górecki > <marmarek@invisiblethingslab.com> this should be rebased on top of Jan's patch. Reviewed-by: Kevin Tian <kevin.tian@intel.com>
On 14.03.2023 02:50, Tian, Kevin wrote: >> From: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> >> Sent: Tuesday, March 14, 2023 9:32 AM >> >> If the scope for IGD's IOMMU contains additional device that doesn't >> actually exist, iommu=no-igfx would not disable that IOMMU. In this >> particular case (Thinkpad x230) it included >> 00:02.1, but there is no such device on this platform. >> Consider only existing devices for "gfx only" check. >> >> Fixes: 2d7f191b392e ("VT-d: generalize and correct "iommu=no-igfx" >> handling") >> Signed-off-by: Marek Marczykowski-Górecki >> <marmarek@invisiblethingslab.com> > > this should be rebased on top of Jan's patch. Right - I guess I could take care of that while applying. But I wonder whether the description wouldn't then want adjusting some as well. Or wait, with the v2 change it should actually have been adjusted already, as the igd_drhd_address determination is now (intentionally) also affected. Jan > Reviewed-by: Kevin Tian <kevin.tian@intel.com>
On 14.03.2023 11:24, Jan Beulich wrote: > On 14.03.2023 02:50, Tian, Kevin wrote: >>> From: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> >>> Sent: Tuesday, March 14, 2023 9:32 AM >>> >>> If the scope for IGD's IOMMU contains additional device that doesn't >>> actually exist, iommu=no-igfx would not disable that IOMMU. In this >>> particular case (Thinkpad x230) it included >>> 00:02.1, but there is no such device on this platform. >>> Consider only existing devices for "gfx only" check. >>> >>> Fixes: 2d7f191b392e ("VT-d: generalize and correct "iommu=no-igfx" >>> handling") >>> Signed-off-by: Marek Marczykowski-Górecki >>> <marmarek@invisiblethingslab.com> >> >> this should be rebased on top of Jan's patch. > > Right - I guess I could take care of that while applying. But I wonder > whether the description wouldn't then want adjusting some as well. Or > wait, with the v2 change it should actually have been adjusted already, > as the igd_drhd_address determination is now (intentionally) also > affected. Since it wasn't clear if/when a v3 would appear, I've done the adjustments myself even if originally I didn't mean to. I've also adjusted the title a little, first and foremost to replace "phantom device" (which has an entirely different meaning in PCI). Jan
diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c index 78c8bad1515a..a8c09c0c84f6 100644 --- a/xen/drivers/passthrough/vtd/dmar.c +++ b/xen/drivers/passthrough/vtd/dmar.c @@ -389,7 +389,7 @@ static int __init acpi_parse_dev_scope( printk(VTDPREFIX " endpoint: %pp\n", &PCI_SBDF(seg, bus, path->dev, path->fn)); - if ( drhd ) + if ( drhd && pci_device_detect(seg, bus, path->dev, path->fn) ) { if ( (seg == 0) && (bus == 0) && (path->dev == 2) && (path->fn == 0) )
If the scope for IGD's IOMMU contains additional device that doesn't actually exist, iommu=no-igfx would not disable that IOMMU. In this particular case (Thinkpad x230) it included 00:02.1, but there is no such device on this platform. Consider only existing devices for "gfx only" check. Fixes: 2d7f191b392e ("VT-d: generalize and correct "iommu=no-igfx" handling") Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> --- v2: - move existence check one level up I have looked at existence check acpi_parse_one_drhd(), but re-using that one wouldn't work for two reasons: - gfx_only logic is very much tied to acpi_parse_dev_scope() - pci_device_detect() in acpi_parse_one_drhd() is skipped in case of (implicit or explicit) iommu=force --- xen/drivers/passthrough/vtd/dmar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)