On Mon, Oct 09, 2017 at 04:20:24PM +0100, Marc Zyngier wrote: > We currently tightly couple dcache clean with icache invalidation, > but KVM could do without the initial flush to PoU, as we've > already flushed things to PoC. > > Let's introduce invalidate_icache_range which is limited to > invalidating the icache from the linear mapping (and thus > has none of the userspace fault handling complexity), and > wire it in KVM instead of flush_icache_range. > > Signed-off-by: Marc Zyngier <[email protected]> > --- > arch/arm64/include/asm/cacheflush.h | 8 ++++++++ > arch/arm64/include/asm/kvm_mmu.h | 4 ++-- > arch/arm64/mm/cache.S | 24 ++++++++++++++++++++++++ > 3 files changed, 34 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/cacheflush.h > b/arch/arm64/include/asm/cacheflush.h > index 76d1cc85d5b1..ad56406944c6 100644 > --- a/arch/arm64/include/asm/cacheflush.h > +++ b/arch/arm64/include/asm/cacheflush.h > @@ -52,6 +52,13 @@ > * - start - virtual start address > * - end - virtual end address > * > + * invalidate_icache_range(start, end) > + * > + * Invalidate the I-cache in the region described by start, end. > + * Linear mapping only! > + * - start - virtual start address > + * - end - virtual end address > + * > * __flush_cache_user_range(start, end) > * > * Ensure coherency between the I-cache and the D-cache in the > @@ -66,6 +73,7 @@ > * - size - region size > */ > extern void flush_icache_range(unsigned long start, unsigned long end); > +extern void invalidate_icache_range(unsigned long start, unsigned long end); > extern void __flush_dcache_area(void *addr, size_t len); > extern void __inval_dcache_area(void *addr, size_t len); > extern void __clean_dcache_area_poc(void *addr, size_t len); > diff --git a/arch/arm64/include/asm/kvm_mmu.h > b/arch/arm64/include/asm/kvm_mmu.h > index 4c4cb4f0e34f..48d31ca2ce9c 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -250,8 +250,8 @@ static inline void __coherent_icache_guest_page(struct > kvm_vcpu *vcpu, > /* PIPT or VPIPT at EL2 (see comment in > __kvm_tlb_flush_vmid_ipa) */ > void *va = page_address(pfn_to_page(pfn)); > > - flush_icache_range((unsigned long)va, > - (unsigned long)va + size); > + invalidate_icache_range((unsigned long)va, > + (unsigned long)va + size); > } > } > > diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S > index 7f1dbe962cf5..0c330666a8c9 100644 > --- a/arch/arm64/mm/cache.S > +++ b/arch/arm64/mm/cache.S > @@ -80,6 +80,30 @@ USER(9f, ic ivau, x4 ) // > invalidate I line PoU > ENDPROC(flush_icache_range) > ENDPROC(__flush_cache_user_range) > > +/* > + * invalidate_icache_range(start,end) > + * > + * Ensure that the I cache is invalid within specified region. This > + * assumes that this is done on the linear mapping. Do not use it > + * on a userspace range, as this may fault horribly. > + * > + * - start - virtual start address of region > + * - end - virtual end address of region > + */ > +ENTRY(invalidate_icache_range) > + icache_line_size x2, x3 > + sub x3, x2, #1 > + bic x4, x0, x3 > +1: > + ic ivau, x4 // invalidate I line PoU > + add x4, x4, x2 > + cmp x4, x1 > + b.lo 1b > + dsb ish > + isb > + ret > +ENDPROC(invalidate_icache_range) > + > /* > * __flush_dcache_area(kaddr, size) > * > -- > 2.14.1 >
Reviewed-by: Christoffer Dall <[email protected]> _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
