On Mon, Jul 24, 2017 at 02:07:51PM -0500, Brijesh Singh wrote: > From: Tom Lendacky <thomas.lendacky@xxxxxxx> > > In order for memory pages to be properly mapped when SEV is active, we > need to use the PAGE_KERNEL protection attribute as the base protection. > This will insure that memory mapping of, e.g. ACPI tables, receives the > proper mapping attributes. > > Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> > Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx> > --- > arch/x86/mm/ioremap.c | 28 ++++++++++++++++++++++++++++ > include/linux/ioport.h | 3 +++ > kernel/resource.c | 17 +++++++++++++++++ > 3 files changed, 48 insertions(+) > > diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c > index c0be7cf..7b27332 100644 > --- a/arch/x86/mm/ioremap.c > +++ b/arch/x86/mm/ioremap.c > @@ -69,6 +69,26 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, > return 0; > } > > +static int __ioremap_res_desc_other(struct resource *res, void *arg) > +{ > + return (res->desc != IORES_DESC_NONE); > +} > + > +/* > + * This function returns true if the target memory is marked as > + * IORESOURCE_MEM and IORESOURCE_BUSY and described as other than > + * IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES). > + */ > +static bool __ioremap_check_if_mem(resource_size_t addr, unsigned long size) > +{ > + u64 start, end; > + > + start = (u64)addr; > + end = start + size - 1; > + > + return (walk_mem_res(start, end, NULL, __ioremap_res_desc_other) == 1); > +} > + > /* > * Remap an arbitrary physical address space into the kernel virtual > * address space. It transparently creates kernel huge I/O mapping when > @@ -146,7 +166,15 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, > pcm = new_pcm; > } > > + /* > + * If the page being mapped is in memory and SEV is active then > + * make sure the memory encryption attribute is enabled in the > + * resulting mapping. > + */ > prot = PAGE_KERNEL_IO; > + if (sev_active() && __ioremap_check_if_mem(phys_addr, size)) > + prot = pgprot_encrypted(prot); Hmm, so this function already does walk_system_ram_range() a bit earlier and now on SEV systems we're going to do it again. Can we make walk_system_ram_range() return a distinct value for SEV systems and act accordingly in __ioremap_caller() instead of repeating the operation? It looks to me like we could... -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) -- -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html