[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] x86/p2m: write_p2m_entry_{pre,post} hooks are HVM-only
commit 9b9ef2388c238a5b0d070a76a50efe696052bc52 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Mon May 3 15:29:49 2021 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Mon May 3 15:29:49 2021 +0200 x86/p2m: write_p2m_entry_{pre,post} hooks are HVM-only Move respective shadow code to its HVM-only source file, thus making it possible to exclude the hooks as well. This then shows that shadow_p2m_init() also isn't needed in !HVM builds. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Acked-by: Tim Deegan <tim@xxxxxxx> --- xen/arch/x86/mm/shadow/common.c | 136 ---------------------------------------- xen/arch/x86/mm/shadow/hvm.c | 136 ++++++++++++++++++++++++++++++++++++++++ xen/include/asm-x86/p2m.h | 4 +- 3 files changed, 137 insertions(+), 139 deletions(-) diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c index 72d3816fcc..b060ebcb72 100644 --- a/xen/arch/x86/mm/shadow/common.c +++ b/xen/arch/x86/mm/shadow/common.c @@ -2289,22 +2289,6 @@ void shadow_prepare_page_type_change(struct domain *d, struct page_info *page, shadow_remove_all_shadows(d, page_to_mfn(page)); } -static void -sh_remove_all_shadows_and_parents(struct domain *d, mfn_t gmfn) -/* Even harsher: this is a HVM page that we thing is no longer a pagetable. - * Unshadow it, and recursively unshadow pages that reference it. */ -{ - sh_remove_shadows(d, gmfn, 0, 1); - /* XXX TODO: - * Rework this hashtable walker to return a linked-list of all - * the shadows it modified, then do breadth-first recursion - * to find the way up to higher-level tables and unshadow them too. - * - * The current code (just tearing down each page's shadows as we - * detect that it is not a pagetable) is correct, but very slow. - * It means extra emulated writes and slows down removal of mappings. */ -} - /**************************************************************************/ /* Reset the up-pointers of every L3 shadow to 0. @@ -3031,126 +3015,6 @@ static int shadow_test_disable(struct domain *d) return ret; } -/**************************************************************************/ -/* P2M map manipulations */ - -/* shadow specific code which should be called when P2M table entry is updated - * with new content. It is responsible for update the entry, as well as other - * shadow processing jobs. - */ - -static void sh_unshadow_for_p2m_change(struct domain *d, unsigned long gfn, - l1_pgentry_t old, l1_pgentry_t new, - unsigned int level) -{ - mfn_t omfn = l1e_get_mfn(old); - unsigned int oflags = l1e_get_flags(old); - p2m_type_t p2mt = p2m_flags_to_type(oflags); - bool flush = false; - - /* - * If there are any shadows, update them. But if shadow_teardown() - * has already been called then it's not safe to try. - */ - if ( unlikely(!d->arch.paging.shadow.total_pages) ) - return; - - switch ( level ) - { - default: - /* - * The following assertion is to make sure we don't step on 1GB host - * page support of HVM guest. - */ - ASSERT(!((oflags & _PAGE_PRESENT) && (oflags & _PAGE_PSE))); - break; - - /* If we're removing an MFN from the p2m, remove it from the shadows too */ - case 1: - if ( (p2m_is_valid(p2mt) || p2m_is_grant(p2mt)) && mfn_valid(omfn) ) - { - sh_remove_all_shadows_and_parents(d, omfn); - if ( sh_remove_all_mappings(d, omfn, _gfn(gfn)) ) - flush = true; - } - break; - - /* - * If we're removing a superpage mapping from the p2m, we need to check - * all the pages covered by it. If they're still there in the new - * scheme, that's OK, but otherwise they must be unshadowed. - */ - case 2: - if ( !(oflags & _PAGE_PRESENT) || !(oflags & _PAGE_PSE) ) - break; - - if ( p2m_is_valid(p2mt) && mfn_valid(omfn) ) - { - unsigned int i; - mfn_t nmfn = l1e_get_mfn(new); - l1_pgentry_t *npte = NULL; - - /* If we're replacing a superpage with a normal L1 page, map it */ - if ( (l1e_get_flags(new) & _PAGE_PRESENT) && - !(l1e_get_flags(new) & _PAGE_PSE) && - mfn_valid(nmfn) ) - npte = map_domain_page(nmfn); - - gfn &= ~(L1_PAGETABLE_ENTRIES - 1); - - for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) - { - if ( !npte || - !p2m_is_ram(p2m_flags_to_type(l1e_get_flags(npte[i]))) || - !mfn_eq(l1e_get_mfn(npte[i]), omfn) ) - { - /* This GFN->MFN mapping has gone away */ - sh_remove_all_shadows_and_parents(d, omfn); - if ( sh_remove_all_mappings(d, omfn, _gfn(gfn + i)) ) - flush = true; - } - omfn = mfn_add(omfn, 1); - } - - if ( npte ) - unmap_domain_page(npte); - } - - break; - } - - if ( flush ) - guest_flush_tlb_mask(d, d->dirty_cpumask); -} - -#if (SHADOW_OPTIMIZATIONS & SHOPT_FAST_FAULT_PATH) -static void -sh_write_p2m_entry_post(struct p2m_domain *p2m, unsigned int oflags) -{ - struct domain *d = p2m->domain; - - /* If we're doing FAST_FAULT_PATH, then shadow mode may have - cached the fact that this is an mmio region in the shadow - page tables. Blow the tables away to remove the cache. - This is pretty heavy handed, but this is a rare operation - (it might happen a dozen times during boot and then never - again), so it doesn't matter too much. */ - if ( d->arch.paging.shadow.has_fast_mmio_entries ) - { - shadow_blow_tables(d); - d->arch.paging.shadow.has_fast_mmio_entries = false; - } -} -#else -# define sh_write_p2m_entry_post NULL -#endif - -void shadow_p2m_init(struct p2m_domain *p2m) -{ - p2m->write_p2m_entry_pre = sh_unshadow_for_p2m_change; - p2m->write_p2m_entry_post = sh_write_p2m_entry_post; -} - /**************************************************************************/ /* Log-dirty mode support */ diff --git a/xen/arch/x86/mm/shadow/hvm.c b/xen/arch/x86/mm/shadow/hvm.c index 7f98286385..d5f42102a0 100644 --- a/xen/arch/x86/mm/shadow/hvm.c +++ b/xen/arch/x86/mm/shadow/hvm.c @@ -773,6 +773,142 @@ void sh_destroy_monitor_table(const struct vcpu *v, mfn_t mmfn, shadow_free(d, mmfn); } +/**************************************************************************/ +/* P2M map manipulations */ + +/* shadow specific code which should be called when P2M table entry is updated + * with new content. It is responsible for update the entry, as well as other + * shadow processing jobs. + */ + +static void +sh_remove_all_shadows_and_parents(struct domain *d, mfn_t gmfn) +/* Even harsher: this is a HVM page that we thing is no longer a pagetable. + * Unshadow it, and recursively unshadow pages that reference it. */ +{ + sh_remove_shadows(d, gmfn, 0, 1); + /* XXX TODO: + * Rework this hashtable walker to return a linked-list of all + * the shadows it modified, then do breadth-first recursion + * to find the way up to higher-level tables and unshadow them too. + * + * The current code (just tearing down each page's shadows as we + * detect that it is not a pagetable) is correct, but very slow. + * It means extra emulated writes and slows down removal of mappings. */ +} + +static void sh_unshadow_for_p2m_change(struct domain *d, unsigned long gfn, + l1_pgentry_t old, l1_pgentry_t new, + unsigned int level) +{ + mfn_t omfn = l1e_get_mfn(old); + unsigned int oflags = l1e_get_flags(old); + p2m_type_t p2mt = p2m_flags_to_type(oflags); + bool flush = false; + + /* + * If there are any shadows, update them. But if shadow_teardown() + * has already been called then it's not safe to try. + */ + if ( unlikely(!d->arch.paging.shadow.total_pages) ) + return; + + switch ( level ) + { + default: + /* + * The following assertion is to make sure we don't step on 1GB host + * page support of HVM guest. + */ + ASSERT(!((oflags & _PAGE_PRESENT) && (oflags & _PAGE_PSE))); + break; + + /* If we're removing an MFN from the p2m, remove it from the shadows too */ + case 1: + if ( (p2m_is_valid(p2mt) || p2m_is_grant(p2mt)) && mfn_valid(omfn) ) + { + sh_remove_all_shadows_and_parents(d, omfn); + if ( sh_remove_all_mappings(d, omfn, _gfn(gfn)) ) + flush = true; + } + break; + + /* + * If we're removing a superpage mapping from the p2m, we need to check + * all the pages covered by it. If they're still there in the new + * scheme, that's OK, but otherwise they must be unshadowed. + */ + case 2: + if ( !(oflags & _PAGE_PRESENT) || !(oflags & _PAGE_PSE) ) + break; + + if ( p2m_is_valid(p2mt) && mfn_valid(omfn) ) + { + unsigned int i; + mfn_t nmfn = l1e_get_mfn(new); + l1_pgentry_t *npte = NULL; + + /* If we're replacing a superpage with a normal L1 page, map it */ + if ( (l1e_get_flags(new) & _PAGE_PRESENT) && + !(l1e_get_flags(new) & _PAGE_PSE) && + mfn_valid(nmfn) ) + npte = map_domain_page(nmfn); + + gfn &= ~(L1_PAGETABLE_ENTRIES - 1); + + for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ ) + { + if ( !npte || + !p2m_is_ram(p2m_flags_to_type(l1e_get_flags(npte[i]))) || + !mfn_eq(l1e_get_mfn(npte[i]), omfn) ) + { + /* This GFN->MFN mapping has gone away */ + sh_remove_all_shadows_and_parents(d, omfn); + if ( sh_remove_all_mappings(d, omfn, _gfn(gfn + i)) ) + flush = true; + } + omfn = mfn_add(omfn, 1); + } + + if ( npte ) + unmap_domain_page(npte); + } + + break; + } + + if ( flush ) + guest_flush_tlb_mask(d, d->dirty_cpumask); +} + +#if (SHADOW_OPTIMIZATIONS & SHOPT_FAST_FAULT_PATH) +static void +sh_write_p2m_entry_post(struct p2m_domain *p2m, unsigned int oflags) +{ + struct domain *d = p2m->domain; + + /* If we're doing FAST_FAULT_PATH, then shadow mode may have + cached the fact that this is an mmio region in the shadow + page tables. Blow the tables away to remove the cache. + This is pretty heavy handed, but this is a rare operation + (it might happen a dozen times during boot and then never + again), so it doesn't matter too much. */ + if ( d->arch.paging.shadow.has_fast_mmio_entries ) + { + shadow_blow_tables(d); + d->arch.paging.shadow.has_fast_mmio_entries = false; + } +} +#else +# define sh_write_p2m_entry_post NULL +#endif + +void shadow_p2m_init(struct p2m_domain *p2m) +{ + p2m->write_p2m_entry_pre = sh_unshadow_for_p2m_change; + p2m->write_p2m_entry_post = sh_write_p2m_entry_post; +} + /**************************************************************************/ /* VRAM dirty tracking support */ int shadow_track_dirty_vram(struct domain *d, diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h index 776d3bb1b5..f33ae2327d 100644 --- a/xen/include/asm-x86/p2m.h +++ b/xen/include/asm-x86/p2m.h @@ -278,7 +278,6 @@ struct p2m_domain { unsigned long first_gfn, unsigned long last_gfn); void (*memory_type_changed)(struct p2m_domain *p2m); -#endif void (*write_p2m_entry_pre)(struct domain *d, unsigned long gfn, l1_pgentry_t old, @@ -286,6 +285,7 @@ struct p2m_domain { unsigned int level); void (*write_p2m_entry_post)(struct p2m_domain *p2m, unsigned int oflags); +#endif #if P2M_AUDIT long (*audit_p2m)(struct p2m_domain *p2m); #endif @@ -796,8 +796,6 @@ int __must_check p2m_set_entry(struct p2m_domain *p2m, gfn_t gfn, mfn_t mfn, #if defined(CONFIG_HVM) /* Set up function pointers for PT implementation: only for use by p2m code */ extern void p2m_pt_init(struct p2m_domain *p2m); -#elif defined(CONFIG_SHADOW_PAGING) -# define p2m_pt_init shadow_p2m_init #else static inline void p2m_pt_init(struct p2m_domain *p2m) {} #endif -- generated by git-patchbot for /home/xen/git/xen.git#master
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