* [Qemu-devel] [PATCH] kernel vfio: PCI ROM size calculation @ 2012-05-12 6:50 Alexey Kardashevskiy 2012-05-14 2:55 ` Alex Williamson 0 siblings, 1 reply; 4+ messages in thread From: Alexey Kardashevskiy @ 2012-05-12 6:50 UTC (permalink / raw) To: Alex Williamson; +Cc: kvm, qemu-devel, Alex Graf, David Gibson The original code calculated the real size of the ROM and passed it to QEMU which tried to do pci_register_bar and failed with error message "ERROR: PCI region size must be pow2". The example card is PCIe Intel E1000E with the ROM size 0x9c00. pci_resource_len seems to be a proper solution. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> --- drivers/vfio/pci/vfio_pci.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index b2f1f3a..6d4a783 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -234,12 +234,9 @@ static long vfio_pci_ioctl(void *device_data, * this gives the user an easy way to determine whether * there's anything here w/o trying to read it. */ if (info.index == VFIO_PCI_ROM_REGION_INDEX) { - void __iomem *io; - size_t size; - - io = pci_map_rom(pdev, &size); - info.size = io ? size : 0; - pci_unmap_rom(pdev, io); + info.size = pci_resource_len(pdev, + PCI_ROM_RESOURCE); + info.flags |= VFIO_PCI_ROM_REGION_INDEX; } else if (flags & IORESOURCE_MEM) { info.size = pci_resource_len(pdev, info.index); info.flags |= (VFIO_REGION_INFO_FLAG_WRITE | -- Alexey ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] kernel vfio: PCI ROM size calculation 2012-05-12 6:50 [Qemu-devel] [PATCH] kernel vfio: PCI ROM size calculation Alexey Kardashevskiy @ 2012-05-14 2:55 ` Alex Williamson 2012-05-14 3:24 ` Alexey Kardashevskiy 0 siblings, 1 reply; 4+ messages in thread From: Alex Williamson @ 2012-05-14 2:55 UTC (permalink / raw) To: Alexey Kardashevskiy; +Cc: David Gibson, qemu-devel, kvm, Alex Graf On Sat, 2012-05-12 at 16:50 +1000, Alexey Kardashevskiy wrote: > The original code calculated the real size of the ROM and passed it to > QEMU which tried to do pci_register_bar and failed with error message > "ERROR: PCI region size must be pow2". > > The example card is PCIe Intel E1000E with the ROM size 0x9c00. > > pci_resource_len seems to be a proper solution. > > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > drivers/vfio/pci/vfio_pci.c | 9 +++------ > 1 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index b2f1f3a..6d4a783 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -234,12 +234,9 @@ static long vfio_pci_ioctl(void *device_data, > * this gives the user an easy way to determine whether > * there's anything here w/o trying to read it. */ This is actually intentional, but maybe isn't the best way to handle it anymore. The cut-off comment above reads: /* Report the actual ROM size instead of the BAR size, * this gives the user an easy way to determine whether * there's anything here w/o trying to read it. */ At the time I added that though, I think we still had a separate ioctl to get the BAR size, so one gave the real size, the other the BAR size. Do we care to expose that ROMs have real size, maybe zero, that doesn't necessarily match pci_resource_len()? Thanks, Alex > if (info.index == VFIO_PCI_ROM_REGION_INDEX) { > - void __iomem *io; > - size_t size; > - > - io = pci_map_rom(pdev, &size); > - info.size = io ? size : 0; > - pci_unmap_rom(pdev, io); > + info.size = pci_resource_len(pdev, > + PCI_ROM_RESOURCE); > + info.flags |= VFIO_PCI_ROM_REGION_INDEX; > } else if (flags & IORESOURCE_MEM) { > info.size = pci_resource_len(pdev, info.index); > info.flags |= (VFIO_REGION_INFO_FLAG_WRITE | > ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] kernel vfio: PCI ROM size calculation 2012-05-14 2:55 ` Alex Williamson @ 2012-05-14 3:24 ` Alexey Kardashevskiy 2012-05-14 4:34 ` Alex Williamson 0 siblings, 1 reply; 4+ messages in thread From: Alexey Kardashevskiy @ 2012-05-14 3:24 UTC (permalink / raw) To: Alex Williamson; +Cc: David Gibson, qemu-devel, kvm, Alex Graf On 14/05/12 12:55, Alex Williamson wrote: > On Sat, 2012-05-12 at 16:50 +1000, Alexey Kardashevskiy wrote: >> The original code calculated the real size of the ROM and passed it to >> QEMU which tried to do pci_register_bar and failed with error message >> "ERROR: PCI region size must be pow2". >> >> The example card is PCIe Intel E1000E with the ROM size 0x9c00. >> >> pci_resource_len seems to be a proper solution. >> >> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> >> --- >> drivers/vfio/pci/vfio_pci.c | 9 +++------ >> 1 files changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c >> index b2f1f3a..6d4a783 100644 >> --- a/drivers/vfio/pci/vfio_pci.c >> +++ b/drivers/vfio/pci/vfio_pci.c >> @@ -234,12 +234,9 @@ static long vfio_pci_ioctl(void *device_data, >> * this gives the user an easy way to determine whether >> * there's anything here w/o trying to read it. */ > > This is actually intentional, but maybe isn't the best way to handle it > anymore. The cut-off comment above reads: > > /* Report the actual ROM size instead of the BAR size, > * this gives the user an easy way to determine whether > * there's anything here w/o trying to read it. */ > > At the time I added that though, I think we still had a separate ioctl > to get the BAR size, so one gave the real size, the other the BAR size. > Do we care to expose that ROMs have real size, maybe zero, that doesn't > necessarily match pci_resource_len()? Thanks, The guest will still see aligned ROM BAR (not real one) and may try to read behind the real end of ROM, and it is allowed while it is still within the BAR, right? > > Alex > >> if (info.index == VFIO_PCI_ROM_REGION_INDEX) { >> - void __iomem *io; >> - size_t size; >> - >> - io = pci_map_rom(pdev, &size); >> - info.size = io ? size : 0; >> - pci_unmap_rom(pdev, io); >> + info.size = pci_resource_len(pdev, >> + PCI_ROM_RESOURCE); >> + info.flags |= VFIO_PCI_ROM_REGION_INDEX; >> } else if (flags & IORESOURCE_MEM) { >> info.size = pci_resource_len(pdev, info.index); >> info.flags |= (VFIO_REGION_INFO_FLAG_WRITE | >> > > > -- Alexey ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] kernel vfio: PCI ROM size calculation 2012-05-14 3:24 ` Alexey Kardashevskiy @ 2012-05-14 4:34 ` Alex Williamson 0 siblings, 0 replies; 4+ messages in thread From: Alex Williamson @ 2012-05-14 4:34 UTC (permalink / raw) To: Alexey Kardashevskiy; +Cc: Alex Graf, qemu-devel, kvm, David Gibson On Mon, 2012-05-14 at 13:24 +1000, Alexey Kardashevskiy wrote: > On 14/05/12 12:55, Alex Williamson wrote: > > On Sat, 2012-05-12 at 16:50 +1000, Alexey Kardashevskiy wrote: > >> The original code calculated the real size of the ROM and passed it to > >> QEMU which tried to do pci_register_bar and failed with error message > >> "ERROR: PCI region size must be pow2". > >> > >> The example card is PCIe Intel E1000E with the ROM size 0x9c00. > >> > >> pci_resource_len seems to be a proper solution. > >> > >> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > >> --- > >> drivers/vfio/pci/vfio_pci.c | 9 +++------ > >> 1 files changed, 3 insertions(+), 6 deletions(-) > >> > >> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > >> index b2f1f3a..6d4a783 100644 > >> --- a/drivers/vfio/pci/vfio_pci.c > >> +++ b/drivers/vfio/pci/vfio_pci.c > >> @@ -234,12 +234,9 @@ static long vfio_pci_ioctl(void *device_data, > >> * this gives the user an easy way to determine whether > >> * there's anything here w/o trying to read it. */ > > > > This is actually intentional, but maybe isn't the best way to handle it > > anymore. The cut-off comment above reads: > > > > /* Report the actual ROM size instead of the BAR size, > > * this gives the user an easy way to determine whether > > * there's anything here w/o trying to read it. */ > > > > At the time I added that though, I think we still had a separate ioctl > > to get the BAR size, so one gave the real size, the other the BAR size. > > Do we care to expose that ROMs have real size, maybe zero, that doesn't > > necessarily match pci_resource_len()? Thanks, > > > The guest will still see aligned ROM BAR (not real one) and may try to read behind the real end of > ROM, and it is allowed while it is still within the BAR, right? Yes. > >> if (info.index == VFIO_PCI_ROM_REGION_INDEX) { > >> - void __iomem *io; > >> - size_t size; > >> - > >> - io = pci_map_rom(pdev, &size); > >> - info.size = io ? size : 0; > >> - pci_unmap_rom(pdev, io); > >> + info.size = pci_resource_len(pdev, > >> + PCI_ROM_RESOURCE); > >> + info.flags |= VFIO_PCI_ROM_REGION_INDEX; > >> } else if (flags & IORESOURCE_MEM) { > >> info.size = pci_resource_len(pdev, info.index); > >> info.flags |= (VFIO_REGION_INFO_FLAG_WRITE | > >> > > > > > > > > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-05-14 4:34 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-05-12 6:50 [Qemu-devel] [PATCH] kernel vfio: PCI ROM size calculation Alexey Kardashevskiy 2012-05-14 2:55 ` Alex Williamson 2012-05-14 3:24 ` Alexey Kardashevskiy 2012-05-14 4:34 ` Alex Williamson
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