On Tue, Sep 17, 2019 at 01:55:59PM +0000, Derrick, Jonathan wrote: > On Tue, 2019-09-17 at 11:41 +0100, Lorenzo Pieralisi wrote: > > On Mon, Sep 16, 2019 at 07:54:35AM -0600, Jon Derrick wrote: > > > The shadow offset scratchpad was moved to 0x2000-0x2010. Update the > > > location to get the correct shadow offset. > > > > Hi Jon, > > > > what does "was moved" mean ? Would this code still work on previous HW ? > > > The previous code won't work on (not yet released) hw. Guests using the > domain will see the wrong offset and enumerate the domain incorrectly.
That's true also for new kernels on _current_ hardware, isn't it ? What I am saying is that there must be a way to detect the right offset from HW probing or firmware otherwise things will break one way of another. > > We must make sure that the address move is managed seamlessly by the > > kernel. > If we need to avoid changing addressing within stable, then that's > fine. But otherwise is there an issue merging with 5.4? See above. Would 5.4 with this patch applied work on systems where the offset is the same as the _current_ one without this patch applied ? > > For the time being I have to drop this fix and it is extremely > > tight to get it in v5.4, I can't send stable changes that we may > > have to revert. > Aren't we in the beginning of the merge window? Yes and that's the problem, patches for v5.4 should have already being queued a while ago, I do not know when Bjorn will send the PR for v5.4 but that's going to happen shortly, I am making an exception to squeeze these patches in since it is vmd only code but still it is very very tight. Thanks, Lorenzo > > Thanks, > > Lorenzo > > > > > Cc: [email protected] # v5.2+ > > > Fixes: 6788958e ("PCI: vmd: Assign membar addresses from shadow > > > registers") > > > Signed-off-by: Jon Derrick <[email protected]> > > > --- > > > drivers/pci/controller/vmd.c | 9 ++++++--- > > > 1 file changed, 6 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > > > index 2e4da3f51d6b..a35d3f3996d7 100644 > > > --- a/drivers/pci/controller/vmd.c > > > +++ b/drivers/pci/controller/vmd.c > > > @@ -31,6 +31,9 @@ > > > #define PCI_REG_VMLOCK 0x70 > > > #define MB2_SHADOW_EN(vmlock) (vmlock & 0x2) > > > > > > +#define MB2_SHADOW_OFFSET 0x2000 > > > +#define MB2_SHADOW_SIZE 16 > > > + > > > enum vmd_features { > > > /* > > > * Device may contain registers which hint the physical location of the > > > @@ -578,7 +581,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, > > > unsigned long features) > > > u32 vmlock; > > > int ret; > > > > > > - membar2_offset = 0x2018; > > > + membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE; > > > ret = pci_read_config_dword(vmd->dev, PCI_REG_VMLOCK, &vmlock); > > > if (ret || vmlock == ~0) > > > return -ENODEV; > > > @@ -590,9 +593,9 @@ static int vmd_enable_domain(struct vmd_dev *vmd, > > > unsigned long features) > > > if (!membar2) > > > return -ENOMEM; > > > offset[0] = vmd->dev->resource[VMD_MEMBAR1].start - > > > - readq(membar2 + 0x2008); > > > + readq(membar2 + MB2_SHADOW_OFFSET); > > > offset[1] = vmd->dev->resource[VMD_MEMBAR2].start - > > > - readq(membar2 + 0x2010); > > > + readq(membar2 + MB2_SHADOW_OFFSET + 8); > > > pci_iounmap(vmd->dev, membar2); > > > } > > > } > > > -- > > > 2.20.1 > > >
