diff options
Diffstat (limited to '0026-x86-Split-cache_flush-out-of-cache_writeback.patch')
| -rw-r--r-- | 0026-x86-Split-cache_flush-out-of-cache_writeback.patch | 294 |
1 files changed, 0 insertions, 294 deletions
diff --git a/0026-x86-Split-cache_flush-out-of-cache_writeback.patch b/0026-x86-Split-cache_flush-out-of-cache_writeback.patch deleted file mode 100644 index 50f70f4..0000000 --- a/0026-x86-Split-cache_flush-out-of-cache_writeback.patch +++ /dev/null @@ -1,294 +0,0 @@ -From 8eafa2d871ae51d461256e4a14175e24df330c70 Mon Sep 17 00:00:00 2001 -From: Andrew Cooper <andrew.cooper3@citrix.com> -Date: Thu, 9 Jun 2022 15:28:48 +0200 -Subject: [PATCH 26/51] x86: Split cache_flush() out of cache_writeback() - -Subsequent changes will want a fully flushing version. - -Use the new helper rather than opencoding it in flush_area_local(). This -resolves an outstanding issue where the conditional sfence is on the wrong -side of the clflushopt loop. clflushopt is ordered with respect to older -stores, not to younger stores. - -Rename gnttab_cache_flush()'s helper to avoid colliding in name. -grant_table.c can see the prototype from cache.h so the build fails -otherwise. - -This is part of XSA-402. - -Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> -Reviewed-by: Jan Beulich <jbeulich@suse.com> -master commit: 9a67ffee3371506e1cbfdfff5b90658d4828f6a2 -master date: 2022-06-09 14:22:38 +0200 ---- - xen/arch/x86/flushtlb.c | 84 ++++++++++++++++++++++++--- - xen/common/grant_table.c | 4 +- - xen/drivers/passthrough/vtd/extern.h | 1 - - xen/drivers/passthrough/vtd/iommu.c | 53 +---------------- - xen/drivers/passthrough/vtd/x86/vtd.c | 5 -- - xen/include/asm-x86/cache.h | 7 +++ - 6 files changed, 88 insertions(+), 66 deletions(-) - -diff --git a/xen/arch/x86/flushtlb.c b/xen/arch/x86/flushtlb.c -index 25798df50f54..0c912b8669f8 100644 ---- a/xen/arch/x86/flushtlb.c -+++ b/xen/arch/x86/flushtlb.c -@@ -234,7 +234,7 @@ unsigned int flush_area_local(const void *va, unsigned int flags) - if ( flags & FLUSH_CACHE ) - { - const struct cpuinfo_x86 *c = ¤t_cpu_data; -- unsigned long i, sz = 0; -+ unsigned long sz = 0; - - if ( order < (BITS_PER_LONG - PAGE_SHIFT) ) - sz = 1UL << (order + PAGE_SHIFT); -@@ -244,13 +244,7 @@ unsigned int flush_area_local(const void *va, unsigned int flags) - c->x86_clflush_size && c->x86_cache_size && sz && - ((sz >> 10) < c->x86_cache_size) ) - { -- alternative("", "sfence", X86_FEATURE_CLFLUSHOPT); -- for ( i = 0; i < sz; i += c->x86_clflush_size ) -- alternative_input(".byte " __stringify(NOP_DS_PREFIX) ";" -- " clflush %0", -- "data16 clflush %0", /* clflushopt */ -- X86_FEATURE_CLFLUSHOPT, -- "m" (((const char *)va)[i])); -+ cache_flush(va, sz); - flags &= ~FLUSH_CACHE; - } - else -@@ -265,6 +259,80 @@ unsigned int flush_area_local(const void *va, unsigned int flags) - return flags; - } - -+void cache_flush(const void *addr, unsigned int size) -+{ -+ /* -+ * This function may be called before current_cpu_data is established. -+ * Hence a fallback is needed to prevent the loop below becoming infinite. -+ */ -+ unsigned int clflush_size = current_cpu_data.x86_clflush_size ?: 16; -+ const void *end = addr + size; -+ -+ addr -= (unsigned long)addr & (clflush_size - 1); -+ for ( ; addr < end; addr += clflush_size ) -+ { -+ /* -+ * Note regarding the "ds" prefix use: it's faster to do a clflush -+ * + prefix than a clflush + nop, and hence the prefix is added instead -+ * of letting the alternative framework fill the gap by appending nops. -+ */ -+ alternative_io("ds; clflush %[p]", -+ "data16 clflush %[p]", /* clflushopt */ -+ X86_FEATURE_CLFLUSHOPT, -+ /* no outputs */, -+ [p] "m" (*(const char *)(addr))); -+ } -+ -+ alternative("", "sfence", X86_FEATURE_CLFLUSHOPT); -+} -+ -+void cache_writeback(const void *addr, unsigned int size) -+{ -+ unsigned int clflush_size; -+ const void *end = addr + size; -+ -+ /* Fall back to CLFLUSH{,OPT} when CLWB isn't available. */ -+ if ( !boot_cpu_has(X86_FEATURE_CLWB) ) -+ return cache_flush(addr, size); -+ -+ /* -+ * This function may be called before current_cpu_data is established. -+ * Hence a fallback is needed to prevent the loop below becoming infinite. -+ */ -+ clflush_size = current_cpu_data.x86_clflush_size ?: 16; -+ addr -= (unsigned long)addr & (clflush_size - 1); -+ for ( ; addr < end; addr += clflush_size ) -+ { -+/* -+ * The arguments to a macro must not include preprocessor directives. Doing so -+ * results in undefined behavior, so we have to create some defines here in -+ * order to avoid it. -+ */ -+#if defined(HAVE_AS_CLWB) -+# define CLWB_ENCODING "clwb %[p]" -+#elif defined(HAVE_AS_XSAVEOPT) -+# define CLWB_ENCODING "data16 xsaveopt %[p]" /* clwb */ -+#else -+# define CLWB_ENCODING ".byte 0x66, 0x0f, 0xae, 0x30" /* clwb (%%rax) */ -+#endif -+ -+#define BASE_INPUT(addr) [p] "m" (*(const char *)(addr)) -+#if defined(HAVE_AS_CLWB) || defined(HAVE_AS_XSAVEOPT) -+# define INPUT BASE_INPUT -+#else -+# define INPUT(addr) "a" (addr), BASE_INPUT(addr) -+#endif -+ -+ asm volatile (CLWB_ENCODING :: INPUT(addr)); -+ -+#undef INPUT -+#undef BASE_INPUT -+#undef CLWB_ENCODING -+ } -+ -+ asm volatile ("sfence" ::: "memory"); -+} -+ - unsigned int guest_flush_tlb_flags(const struct domain *d) - { - bool shadow = paging_mode_shadow(d); -diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c -index 66f8ce71741c..4c742cd8fe81 100644 ---- a/xen/common/grant_table.c -+++ b/xen/common/grant_table.c -@@ -3431,7 +3431,7 @@ gnttab_swap_grant_ref(XEN_GUEST_HANDLE_PARAM(gnttab_swap_grant_ref_t) uop, - return 0; - } - --static int cache_flush(const gnttab_cache_flush_t *cflush, grant_ref_t *cur_ref) -+static int _cache_flush(const gnttab_cache_flush_t *cflush, grant_ref_t *cur_ref) - { - struct domain *d, *owner; - struct page_info *page; -@@ -3525,7 +3525,7 @@ gnttab_cache_flush(XEN_GUEST_HANDLE_PARAM(gnttab_cache_flush_t) uop, - return -EFAULT; - for ( ; ; ) - { -- int ret = cache_flush(&op, cur_ref); -+ int ret = _cache_flush(&op, cur_ref); - - if ( ret < 0 ) - return ret; -diff --git a/xen/drivers/passthrough/vtd/extern.h b/xen/drivers/passthrough/vtd/extern.h -index 01e010a10d61..401079299725 100644 ---- a/xen/drivers/passthrough/vtd/extern.h -+++ b/xen/drivers/passthrough/vtd/extern.h -@@ -76,7 +76,6 @@ int __must_check qinval_device_iotlb_sync(struct vtd_iommu *iommu, - struct pci_dev *pdev, - u16 did, u16 size, u64 addr); - --unsigned int get_cache_line_size(void); - void flush_all_cache(void); - - uint64_t alloc_pgtable_maddr(unsigned long npages, nodeid_t node); -diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c -index 8975c1de61bc..bc377c9bcfa4 100644 ---- a/xen/drivers/passthrough/vtd/iommu.c -+++ b/xen/drivers/passthrough/vtd/iommu.c -@@ -31,6 +31,7 @@ - #include <xen/pci.h> - #include <xen/pci_regs.h> - #include <xen/keyhandler.h> -+#include <asm/cache.h> - #include <asm/msi.h> - #include <asm/nops.h> - #include <asm/irq.h> -@@ -206,54 +207,6 @@ static void check_cleanup_domid_map(const struct domain *d, - } - } - --static void sync_cache(const void *addr, unsigned int size) --{ -- static unsigned long clflush_size = 0; -- const void *end = addr + size; -- -- if ( clflush_size == 0 ) -- clflush_size = get_cache_line_size(); -- -- addr -= (unsigned long)addr & (clflush_size - 1); -- for ( ; addr < end; addr += clflush_size ) --/* -- * The arguments to a macro must not include preprocessor directives. Doing so -- * results in undefined behavior, so we have to create some defines here in -- * order to avoid it. -- */ --#if defined(HAVE_AS_CLWB) --# define CLWB_ENCODING "clwb %[p]" --#elif defined(HAVE_AS_XSAVEOPT) --# define CLWB_ENCODING "data16 xsaveopt %[p]" /* clwb */ --#else --# define CLWB_ENCODING ".byte 0x66, 0x0f, 0xae, 0x30" /* clwb (%%rax) */ --#endif -- --#define BASE_INPUT(addr) [p] "m" (*(const char *)(addr)) --#if defined(HAVE_AS_CLWB) || defined(HAVE_AS_XSAVEOPT) --# define INPUT BASE_INPUT --#else --# define INPUT(addr) "a" (addr), BASE_INPUT(addr) --#endif -- /* -- * Note regarding the use of NOP_DS_PREFIX: it's faster to do a clflush -- * + prefix than a clflush + nop, and hence the prefix is added instead -- * of letting the alternative framework fill the gap by appending nops. -- */ -- alternative_io_2(".byte " __stringify(NOP_DS_PREFIX) "; clflush %[p]", -- "data16 clflush %[p]", /* clflushopt */ -- X86_FEATURE_CLFLUSHOPT, -- CLWB_ENCODING, -- X86_FEATURE_CLWB, /* no outputs */, -- INPUT(addr)); --#undef INPUT --#undef BASE_INPUT --#undef CLWB_ENCODING -- -- alternative_2("", "sfence", X86_FEATURE_CLFLUSHOPT, -- "sfence", X86_FEATURE_CLWB); --} -- - /* Allocate page table, return its machine address */ - uint64_t alloc_pgtable_maddr(unsigned long npages, nodeid_t node) - { -@@ -273,7 +226,7 @@ uint64_t alloc_pgtable_maddr(unsigned long npages, nodeid_t node) - clear_page(vaddr); - - if ( (iommu_ops.init ? &iommu_ops : &vtd_ops)->sync_cache ) -- sync_cache(vaddr, PAGE_SIZE); -+ cache_writeback(vaddr, PAGE_SIZE); - unmap_domain_page(vaddr); - cur_pg++; - } -@@ -1305,7 +1258,7 @@ int __init iommu_alloc(struct acpi_drhd_unit *drhd) - iommu->nr_pt_levels = agaw_to_level(agaw); - - if ( !ecap_coherent(iommu->ecap) ) -- vtd_ops.sync_cache = sync_cache; -+ vtd_ops.sync_cache = cache_writeback; - - /* allocate domain id bitmap */ - iommu->domid_bitmap = xzalloc_array(unsigned long, BITS_TO_LONGS(nr_dom)); -diff --git a/xen/drivers/passthrough/vtd/x86/vtd.c b/xen/drivers/passthrough/vtd/x86/vtd.c -index 6681dccd6970..55f0faa521cb 100644 ---- a/xen/drivers/passthrough/vtd/x86/vtd.c -+++ b/xen/drivers/passthrough/vtd/x86/vtd.c -@@ -47,11 +47,6 @@ void unmap_vtd_domain_page(const void *va) - unmap_domain_page(va); - } - --unsigned int get_cache_line_size(void) --{ -- return ((cpuid_ebx(1) >> 8) & 0xff) * 8; --} -- - void flush_all_cache() - { - wbinvd(); -diff --git a/xen/include/asm-x86/cache.h b/xen/include/asm-x86/cache.h -index 1f7173d8c72c..e4770efb22b9 100644 ---- a/xen/include/asm-x86/cache.h -+++ b/xen/include/asm-x86/cache.h -@@ -11,4 +11,11 @@ - - #define __read_mostly __section(".data.read_mostly") - -+#ifndef __ASSEMBLY__ -+ -+void cache_flush(const void *addr, unsigned int size); -+void cache_writeback(const void *addr, unsigned int size); -+ -+#endif -+ - #endif --- -2.35.1 - |