On Fri, Jul 7, 2023 at 10:47 AM bibo mao <maobibo@xxxxxxxxxxx> wrote: > > Bjourn, Hucai, > > ping again. > > The is such issue on only LoongArch system since 16K page size is used. > > Should we add code in general framework or in LoongArch specified code > in v1? Though I still don't know why others have no problems. But it is surely a bug on LoongArch. So if Bjorn has no objections, please use the old method (just like v1 but you can simply align to page size unconditionally). Huacai > > If you do not think that it is problem, I can give up. LoongArch system > is not only for myself own, I do not care about it also since LoongArch > Maintainer think it is not a issue. > > Regards > Bibo Mao > > 在 2023/6/26 09:30, bibo mao 写道: > > gentle ping. > > > > 在 2023/6/19 09:47, Bibo Mao 写道: > >> Some PCI devices have only 4K memory space size, it is normal in general > >> machines and aligned with page size. However some architectures which > >> support different page size, default page size on LoongArch is 16K, and > >> ARM64 supports page size varying from 4K to 64K. On machines where larger > >> page size is use, memory space region of two different pci devices may be > >> in one page. It is not safe with mmu protection, also VFIO pci device > >> driver requires base address of pci memory space page aligned, so that it > >> can be memory mapped to qemu user space when it is passed-through to vm. > >> > >> It consumes more pci memory resource with page size alignment requirement, > >> here extra option PCI_MEMRES_PAGE_ALIGN is added, it can be enabled by > >> different architectures, currently arm64/loongarch enable this option. > >> > >> Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx> > >> Reviewed-by: Huacai Chen <chenhuacai@xxxxxxxxxxx> > >> --- > >> Change history > >> v5: enable option PCI_MEMRES_PAGE_ALIGN on arm64. Verified on LoongArch > >> and pass to compile on arm64 with defconfig > >> > >> v4: add extra kernel option PCI_MEMRES_PAGE_ALIGN to set memory resource > >> page aligned > >> > >> v3: move alignment requirement to generic pci code > >> > >> v2: add pci resource alignment requirement in arch specified function > >> pcibios_align_resource on arm64/LoongArch platforms > >> > >> --- > >> arch/arm64/Kconfig | 1 + > >> arch/loongarch/Kconfig | 1 + > >> drivers/pci/Kconfig | 3 +++ > >> drivers/pci/setup-res.c | 7 +++++++ > >> 4 files changed, 12 insertions(+) > >> > >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > >> index 343e1e1cae10..24858bbf2b72 100644 > >> --- a/arch/arm64/Kconfig > >> +++ b/arch/arm64/Kconfig > >> @@ -232,6 +232,7 @@ config ARM64 > >> select OF_EARLY_FLATTREE > >> select PCI_DOMAINS_GENERIC if PCI > >> select PCI_ECAM if (ACPI && PCI) > >> + select PCI_MEMRES_PAGE_ALIGN if PCI > >> select PCI_SYSCALL if PCI > >> select POWER_RESET > >> select POWER_SUPPLY > >> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > >> index d38b066fc931..7dbde5e5b351 100644 > >> --- a/arch/loongarch/Kconfig > >> +++ b/arch/loongarch/Kconfig > >> @@ -140,6 +140,7 @@ config LOONGARCH > >> select PCI_DOMAINS_GENERIC > >> select PCI_ECAM if ACPI > >> select PCI_LOONGSON > >> + select PCI_MEMRES_PAGE_ALIGN > >> select PCI_MSI_ARCH_FALLBACKS > >> select PCI_QUIRKS > >> select PERF_USE_VMALLOC > >> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig > >> index 9309f2469b41..9be5f85ff9dc 100644 > >> --- a/drivers/pci/Kconfig > >> +++ b/drivers/pci/Kconfig > >> @@ -128,6 +128,9 @@ config PCI_LOCKLESS_CONFIG > >> config PCI_BRIDGE_EMUL > >> bool > >> > >> +config PCI_MEMRES_PAGE_ALIGN > >> + bool > >> + > >> config PCI_IOV > >> bool "PCI IOV support" > >> select PCI_ATS > >> diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c > >> index 967f9a758923..6ad76734a670 100644 > >> --- a/drivers/pci/setup-res.c > >> +++ b/drivers/pci/setup-res.c > >> @@ -339,6 +339,13 @@ int pci_assign_resource(struct pci_dev *dev, int resno) > >> return -EINVAL; > >> } > >> > >> +#ifdef CONFIG_PCI_MEMRES_PAGE_ALIGN > >> + /* > >> + * force minimum page alignment for vfio pci usage > >> + */ > >> + if (res->flags & IORESOURCE_MEM) > >> + align = max_t(resource_size_t, PAGE_SIZE, align); > >> +#endif > >> size = resource_size(res); > >> ret = _pci_assign_resource(dev, resno, size, align); > >> > > > > _______________________________________________ > > Loongson-kernel mailing list -- loongson-kernel@xxxxxxxxxxxxxxxxx > > To unsubscribe send an email to loongson-kernel-leave@xxxxxxxxxxxxxxxxx > >
