Thanks, will refine in v2. On Thu, Aug 9, 2018, 18:49 Burakov, Anatoly <anatoly.bura...@intel.com> wrote:
> On 05-Aug-18 7:41 PM, Drocula wrote: > > The kernel version 4.14 released with the support of 5-level paging. > > When PML5 enabled, user-space virtual addresses uses up to 56 bits. > > see kernel's Documentation/x86/x86_64/mm.txt. > > > > Signed-off-by: Drocula <quze...@gmail.com> > > --- > > drivers/bus/pci/linux/pci.c | 27 +++++++++++++++++++++++++-- > > 1 file changed, 25 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c > > index 004600f..8913d6d 100644 > > --- a/drivers/bus/pci/linux/pci.c > > +++ b/drivers/bus/pci/linux/pci.c > > @@ -4,6 +4,7 @@ > > > > #include <string.h> > > #include <dirent.h> > > +#include <sys/mman.h> > > > > #include <rte_log.h> > > #include <rte_bus.h> > > @@ -553,12 +554,34 @@ > > } > > > > #if defined(RTE_ARCH_X86) > > +/* > > + * Try to detect whether the system uses 5-level page table. > > + */ > > +static bool > > +system_uses_PML5(void) > > +{ > > + void *page_4k, *mask = (void *)0xf0000000000000; > > + page_4k = mmap(mask, 4096, PROT_READ | PROT_WRITE, > > + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); > > + > > + if (page_4k == (void *) -1) > > + return false; > > Shouldn't this be MAP_FAILED? > > > + munmap(page_4k, 4096); > > + > > + if ((unsigned long)page_4k & (unsigned long)mask) > > + return true; > > + return false; > > +} > > + > > static bool > > pci_one_device_iommu_support_va(struct rte_pci_device *dev) > > { > > #define VTD_CAP_MGAW_SHIFT 16 > > #define VTD_CAP_MGAW_MASK (0x3fULL << VTD_CAP_MGAW_SHIFT) > > -#define X86_VA_WIDTH 47 /* From Documentation/x86/x86_64/mm.txt */ > > +/* From Documentation/x86/x86_64/mm.txt */ > > +#define X86_VA_WIDTH_PML4 47 > > +#define X86_VA_WIDTH_PML5 56 > > + > > struct rte_pci_addr *addr = &dev->addr; > > char filename[PATH_MAX]; > > FILE *fp; > > @@ -589,7 +612,7 @@ > > fclose(fp); > > > > mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + > 1; > > - if (mgaw < X86_VA_WIDTH) > > + if (mgaw < (system_uses_PML5() ? X86_VA_WIDTH_PML5 : > X86_VA_WIDTH_PML4)) > > This is perhaps nitpicking and a question of personal preferences, but i > think storing this in a var would be more readable than doing ternary > operator inside of an if statement. > > > return false; > > > > return true; > > > > > -- > Thanks, > Anatoly >