From 4fee94736603cd6fd83c1ea1ee0388d1d2dbe11b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 23 Oct 2017 17:11:16 +0100 Subject: arm64: KVM: Add invalidate_icache_range helper 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. Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm64/include/asm/assembler.h | 21 +++++++++++++++++++++ arch/arm64/include/asm/cacheflush.h | 7 +++++++ arch/arm64/include/asm/kvm_mmu.h | 4 ++-- arch/arm64/mm/cache.S | 32 ++++++++++++++++++++++---------- 4 files changed, 52 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index aef72d886677..0884e1fdfd30 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -387,6 +387,27 @@ alternative_endif dsb \domain .endm +/* + * Macro to perform an instruction cache maintenance for the interval + * [start, end) + * + * start, end: virtual addresses describing the region + * label: A label to branch to on user fault. + * Corrupts: tmp1, tmp2 + */ + .macro invalidate_icache_by_line start, end, tmp1, tmp2, label + icache_line_size \tmp1, \tmp2 + sub \tmp2, \tmp1, #1 + bic \tmp2, \start, \tmp2 +9997: +USER(\label, ic ivau, \tmp2) // invalidate I line PoU + add \tmp2, \tmp2, \tmp1 + cmp \tmp2, \end + b.lo 9997b + dsb ish + isb + .endm + /* * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present */ diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index 955130762a3c..bef9f418f089 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -52,6 +52,12 @@ * - start - virtual start address * - end - virtual end address * + * invalidate_icache_range(start, end) + * + * Invalidate the I-cache in the region described by start, end. + * - 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 +72,7 @@ * - size - region size */ extern void flush_icache_range(unsigned long start, unsigned long end); +extern int 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 8034b96fb3a4..56b3e03c85e7 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -250,8 +250,8 @@ static inline void __invalidate_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..bedd23da83f4 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -60,16 +60,7 @@ user_alt 9f, "dc cvau, x4", "dc civac, x4", ARM64_WORKAROUND_CLEAN_CACHE b.lo 1b dsb ish - icache_line_size x2, x3 - sub x3, x2, #1 - bic x4, x0, x3 -1: -USER(9f, ic ivau, x4 ) // invalidate I line PoU - add x4, x4, x2 - cmp x4, x1 - b.lo 1b - dsb ish - isb + invalidate_icache_by_line x0, x1, x2, x3, 9f mov x0, #0 1: uaccess_ttbr0_disable x1 @@ -80,6 +71,27 @@ 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. + * + * - start - virtual start address of region + * - end - virtual end address of region + */ +ENTRY(invalidate_icache_range) + uaccess_ttbr0_enable x2, x3 + + invalidate_icache_by_line x0, x1, x2, x3, 2f + mov x0, xzr +1: + uaccess_ttbr0_disable x1 + ret +2: + mov x0, #-EFAULT + b 1b +ENDPROC(invalidate_icache_range) + /* * __flush_dcache_area(kaddr, size) * -- cgit