| Message ID | 20240412084213.1733764-7-steven.price@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Support for running as a guest in Arm CCA | expand |
On Fri, Apr 12, 2024 at 09:42:05AM +0100, Steven Price wrote: > Override the set_fixmap_io to set shared permission for the host > in case of a CC guest. For now we mark it shared unconditionally. > Future changes could filter the physical address and make the > decision accordingly. [...] > +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys) > +{ > + pgprot_t prot = FIXMAP_PAGE_IO; > + > + /* > + * For now we consider all I/O as non-secure. For future > + * filter the I/O base for setting appropriate permissions. > + */ > + prot = __pgprot(pgprot_val(prot) | PROT_NS_SHARED); > + > + return __set_fixmap(idx, phys, prot); > +} I looked through the patches and could not find any place where this function does anything different as per the commit log suggestion. Can we just update FIXMAP_PAGE_IO for now until you have a clear use-case?
On 13/05/2024 17:14, Catalin Marinas wrote: > On Fri, Apr 12, 2024 at 09:42:05AM +0100, Steven Price wrote: >> Override the set_fixmap_io to set shared permission for the host >> in case of a CC guest. For now we mark it shared unconditionally. >> Future changes could filter the physical address and make the >> decision accordingly. > [...] >> +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys) >> +{ >> + pgprot_t prot = FIXMAP_PAGE_IO; >> + >> + /* >> + * For now we consider all I/O as non-secure. For future >> + * filter the I/O base for setting appropriate permissions. >> + */ >> + prot = __pgprot(pgprot_val(prot) | PROT_NS_SHARED); >> + >> + return __set_fixmap(idx, phys, prot); >> +} > > I looked through the patches and could not find any place where this > function does anything different as per the commit log suggestion. Can > we just update FIXMAP_PAGE_IO for now until you have a clear use-case? > This gets used by the earlycon mapping. The commit description could be made clear. We may have to revisit this code to optionally apply the PROT_NS_SHARED attribute, depending on whether this is a "protected MMIO" or not. Suzuki
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h index 87e307804b99..f765943b088c 100644 --- a/arch/arm64/include/asm/fixmap.h +++ b/arch/arm64/include/asm/fixmap.h @@ -107,7 +107,9 @@ void __init early_fixmap_init(void); #define __late_set_fixmap __set_fixmap #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR) -extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); +#define set_fixmap_io set_fixmap_io +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys); +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); #include <asm-generic/fixmap.h> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 495b732d5af3..79d84db9ffcb 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1179,6 +1179,19 @@ void vmemmap_free(unsigned long start, unsigned long end, } #endif /* CONFIG_MEMORY_HOTPLUG */ +void set_fixmap_io(enum fixed_addresses idx, phys_addr_t phys) +{ + pgprot_t prot = FIXMAP_PAGE_IO; + + /* + * For now we consider all I/O as non-secure. For future + * filter the I/O base for setting appropriate permissions. + */ + prot = __pgprot(pgprot_val(prot) | PROT_NS_SHARED); + + return __set_fixmap(idx, phys, prot); +} + int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) { pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot));