在 2019年04月15日 23:41, Borislav Petkov 写道: > On Mon, Apr 15, 2019 at 08:22:22PM +0800, lijiang wrote: >> They are different problems. > > Aha, so we're getting closer. You should've lead with that! > >> The first problem is that passes the e820 reserved ranges to the second kernel, > > Passes or *doesn't* pass? > > Because from all the staring, it wants to pass the reserved ranges. > >> for this case, it is good enough to use the IORES_DESC_RESERVED, which >> can ensure that exactly matches the reserved resource ranges when >> walking through iomem resources. > > Ok. > >> The second problem is about the SEV case. Now, the IORES_DESC_RESERVED has been >> created for the reserved areas, therefore the check needs to be expanded so that >> these areas are not mapped encrypted when using ioremap(). >> >> +static int __ioremap_check_desc_none_and_reserved(struct resource *res) > > That name is crap. If you need to add another desc type, it becomes > wrong again. And that whole code around flags->desc_other is just silly: > > Make that machinery around it something like this: > > struct ioremap_desc { > u64 flags; > }; > > instead of "struct ioremap_mem_flags" and that struct ioremap_desc is an > ioremap descriptor which will carry all kinds of settings. system_ram > can then be a simple flag too. > > __ioremap_caller() will hand it down to __ioremap_check_mem() etc > and there it will set flags like IOREMAP_DESC_MAP_ENCRYPTED or > IOREMAP_DESC_MAP_DECRYPTED and this way you'll have it explicit and > clear in __ioremap_caller(): > > if ((sev_active() && > (io_desc.flags & IOREMAP_DESC_MAP_ENCRYPTED)) || > encrypted) > prot = pgprot_encrypted(prot); > > But that would need a pre-patch which does that conversion. > Thanks for your comment. Based on the above description, i made a draft patch, please refer to it. But it seems that the code has been changed a lot. diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 0029604af8a4..04217b61635e 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -27,9 +27,8 @@ #include "physaddr.h" -struct ioremap_mem_flags { - bool system_ram; - bool desc_other; +struct ioremap_desc { + u64 flags; }; /* @@ -61,13 +60,13 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, return err; } -static bool __ioremap_check_ram(struct resource *res) +static unsigned long __ioremap_check_ram(struct resource *res) { unsigned long start_pfn, stop_pfn; unsigned long i; if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM) - return false; + return IOREMAP_DESC_MAP_NONE; start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT; stop_pfn = (res->end + 1) >> PAGE_SHIFT; @@ -75,28 +74,44 @@ static bool __ioremap_check_ram(struct resource *res) for (i = 0; i < (stop_pfn - start_pfn); ++i) if (pfn_valid(start_pfn + i) && !PageReserved(pfn_to_page(start_pfn + i))) - return true; + return IOREMAP_DESC_MAP_SYSTEM_RAM_USING; } - return false; + return IOREMAP_DESC_MAP_NONE; } -static int __ioremap_check_desc_other(struct resource *res) +/* + * Originally, these areas described as IORES_DESC_NONE are not mapped + * as encrypted when using ioremap(), for example, E820_TYPE_{RESERVED, + * RESERVED_KERN,RAM,UNUSABLE}, etc. It checks for a resource that is + * not described as IORES_DESC_NONE, which can make sure the reserved + * areas are not mapped as encrypted when using ioremap(). + * + * Now IORES_DESC_RESERVED has been created for the reserved areas so + * the check needs to be expanded so that these areas are not mapped + * encrypted when using ioremap(). + */ +static unsigned long __ioremap_check_desc(struct resource *res) { - return (res->desc != IORES_DESC_NONE); + if ((res->desc != IORES_DESC_NONE) && + (res->desc != IORES_DESC_RESERVED)) + return IOREMAP_DESC_MAP_ENCRYPTED; + + return IOREMAP_DESC_MAP_NONE; } static int __ioremap_res_check(struct resource *res, void *arg) { - struct ioremap_mem_flags *flags = arg; + struct ioremap_desc *desc = arg; - if (!flags->system_ram) - flags->system_ram = __ioremap_check_ram(res); + if (!(desc->flags & IOREMAP_DESC_MAP_SYSTEM_RAM_USING)) + desc->flags |= __ioremap_check_ram(res); - if (!flags->desc_other) - flags->desc_other = __ioremap_check_desc_other(res); + if (!(desc->flags & IOREMAP_DESC_MAP_ENCRYPTED)) + desc->flags |= __ioremap_check_desc(res); - return flags->system_ram && flags->desc_other; + return ((desc->flags & IOREMAP_DESC_MAP_SYSTEM_RAM_USING) && + (desc->flags & IOREMAP_DESC_MAP_ENCRYPTED)) } /* @@ -105,13 +120,13 @@ static int __ioremap_res_check(struct resource *res, void *arg) * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES). */ static void __ioremap_check_mem(resource_size_t addr, unsigned long size, - struct ioremap_mem_flags *flags) + struct ioremap_desc *desc) { u64 start, end; start = (u64)addr; end = start + size - 1; - memset(flags, 0, sizeof(*flags)); + memset(desc, 0, sizeof(*desc)); walk_mem_res(start, end, flags, __ioremap_res_check); } @@ -138,7 +153,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, resource_size_t last_addr; const resource_size_t unaligned_phys_addr = phys_addr; const unsigned long unaligned_size = size; - struct ioremap_mem_flags mem_flags; + struct ioremap_desc io_desc; struct vm_struct *area; enum page_cache_mode new_pcm; pgprot_t prot; @@ -157,12 +172,12 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, return NULL; } - __ioremap_check_mem(phys_addr, size, &mem_flags); + __ioremap_check_mem(phys_addr, size, &io_desc); /* * Don't allow anybody to remap normal RAM that we're using.. */ - if (mem_flags.system_ram) { + if (io_desc.flags & IOREMAP_DESC_MAP_SYSTEM_RAM_USING) { WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", &phys_addr, &last_addr); return NULL; @@ -200,7 +215,9 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, * resulting mapping. */ prot = PAGE_KERNEL_IO; - if ((sev_active() && mem_flags.desc_other) || encrypted) + if ((sev_active() && + (io_desc.flags & IOREMAP_DESC_MAP_ENCRYPTED)) || + encrypted) prot = pgprot_encrypted(prot); switch (pcm) { diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 6ed59de48bd5..48b2d21ad9e5 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -136,6 +136,15 @@ enum { IORES_DESC_RESERVED = 8, }; +/* + * IORemap Descriptors Helper + */ +enum { + IOREMAP_DESC_MAP_NONE = 0, + IOREMAP_DESC_MAP_SYSTEM_RAM_USING = 1, + IOREMAP_DESC_MAP_ENCRYPTED = 2, +}; + /* helpers to define resources */ #define DEFINE_RES_NAMED(_start, _size, _name, _flags) \ { \ Are you sure about this changes? Or Do other reviewers have any suggestions? Thanks. >> Maybe i should split it into two patches. The change of >> __ioremap_check_desc_none_and_reserved() should be a separate patch. >> Any idea? > > See above and yes, definitely separate patches. > OK. Thank you very much. Lianbo _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec