{"id":2216021,"url":"http://patchwork.ozlabs.org/api/patches/2216021/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260325164453.72127-14-pbonzini@redhat.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260325164453.72127-14-pbonzini@redhat.com>","list_archive_url":null,"date":"2026-03-25T16:44:47","name":"[PULL,13/19] target/i386: emulate: segmentation rework","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"559464fcbdb05f9d3b4030dad4c157e4c0656287","submitter":{"id":2701,"url":"http://patchwork.ozlabs.org/api/people/2701/?format=json","name":"Paolo Bonzini","email":"pbonzini@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260325164453.72127-14-pbonzini@redhat.com/mbox/","series":[{"id":497473,"url":"http://patchwork.ozlabs.org/api/series/497473/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=497473","date":"2026-03-25T16:44:34","name":"[PULL,01/19] tests/functional: preserve PYTHONPATH entries","version":1,"mbox":"http://patchwork.ozlabs.org/series/497473/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2216021/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2216021/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 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5b1f17b1804b1-48715fc38f3mr62050785e9.4.1774457120733;\n Wed, 25 Mar 2026 09:45:20 -0700 (PDT)","by 2002:a05:600c:3d90:b0:485:2a4b:7bc3 with SMTP id\n 5b1f17b1804b1-48715fc38f3mr62050135e9.4.1774457120072;\n Wed, 25 Mar 2026 09:45:20 -0700 (PDT)"],"From":"Paolo Bonzini ","To":"qemu-devel@nongnu.org","Cc":"Mohamed Mediouni ","Subject":"[PULL 13/19] target/i386: emulate: segmentation rework","Date":"Wed, 25 Mar 2026 17:44:47 +0100","Message-ID":"<20260325164453.72127-14-pbonzini@redhat.com>","X-Mailer":"git-send-email 2.53.0","In-Reply-To":"<20260325164453.72127-1-pbonzini@redhat.com>","References":"<20260325164453.72127-1-pbonzini@redhat.com>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Received-SPF":"pass client-ip=170.10.129.124;\n envelope-from=pbonzini@redhat.com;\n helo=us-smtp-delivery-124.mimecast.com","X-Spam_score_int":"-20","X-Spam_score":"-2.1","X-Spam_bar":"--","X-Spam_report":"(-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"From: Mohamed Mediouni \n\nMake accesses to segments all go through read_segment_descriptor\nto be able to fetch segment state on-demand.\n\nSwitch away from SegmentCache to the x86_segment_descriptor\nthat is already used by read_segment_descriptor.\n\nSigned-off-by: Mohamed Mediouni \nLink: https://lore.kernel.org/r/20260324151323.74473-11-mohamed@unpredictable.fr\nSigned-off-by: Paolo Bonzini \n---\n target/i386/emulate/x86_helpers.c | 50 ++++++++++++-------------------\n 1 file changed, 19 insertions(+), 31 deletions(-)","diff":"diff --git a/target/i386/emulate/x86_helpers.c b/target/i386/emulate/x86_helpers.c\nindex c817015ef92..63bae3582fe 100644\n--- a/target/i386/emulate/x86_helpers.c\n+++ b/target/i386/emulate/x86_helpers.c\n@@ -43,49 +43,37 @@ static CpuMode cpu_mode(CPUState *cpu)\n return m;\n }\n \n-static bool segment_type_ro(const SegmentCache *seg)\n+static bool segment_type_ro(const x86_segment_descriptor desc)\n {\n- uint32_t type_ = (seg->flags >> DESC_TYPE_SHIFT) & 15;\n+ uint32_t type_ = desc.type;\n return (type_ & (~RWRX_SEGMENT_TYPE)) == 0;\n }\n \n-static bool segment_type_code(const SegmentCache *seg)\n+static bool segment_type_code(const x86_segment_descriptor desc)\n {\n- uint32_t type_ = (seg->flags >> DESC_TYPE_SHIFT) & 15;\n+ uint32_t type_ = desc.type;\n return (type_ & CODE_SEGMENT_TYPE) != 0;\n }\n \n-static bool segment_expands_down(const SegmentCache *seg)\n+static bool segment_expands_down(const x86_segment_descriptor desc)\n {\n- uint32_t type_ = (seg->flags >> DESC_TYPE_SHIFT) & 15;\n+ uint32_t type_ = desc.type;\n \n- if (segment_type_code(seg)) {\n+ if (segment_type_code(desc)) {\n return false;\n }\n \n return (type_ & EXPAND_DOWN_SEGMENT_TYPE) != 0;\n }\n \n-static uint32_t segment_limit(const SegmentCache *seg)\n+static uint8_t segment_db(const x86_segment_descriptor desc)\n {\n- uint32_t limit = seg->limit;\n- uint32_t granularity = (seg->flags & DESC_G_MASK) != 0;\n-\n- if (granularity != 0) {\n- limit = (limit << 12) | 0xFFF;\n- }\n-\n- return limit;\n+ return desc.db;\n }\n \n-static uint8_t segment_db(const SegmentCache *seg)\n+static uint32_t segment_max_limit(const x86_segment_descriptor desc)\n {\n- return (seg->flags >> DESC_B_SHIFT) & 1;\n-}\n-\n-static uint32_t segment_max_limit(const SegmentCache *seg)\n-{\n- if (segment_db(seg) != 0) {\n+ if (segment_db(desc) != 0) {\n return 0xFFFFFFFF;\n }\n return 0xFFFF;\n@@ -96,15 +84,15 @@ static int linearize(CPUState *cpu,\n X86Seg seg_idx)\n {\n enum CpuMode mode;\n- X86CPU *x86_cpu = X86_CPU(cpu);\n- CPUX86State *env = &x86_cpu->env;\n- SegmentCache *seg = &env->segs[seg_idx];\n- target_ulong base = seg->base;\n+ struct x86_segment_descriptor desc;\n+ target_ulong base;\n target_ulong logical_addr_32b;\n uint32_t limit;\n /* TODO: the emulator will not pass us \"write\" indicator yet */\n bool write = false;\n \n+ emul_ops->read_segment_descriptor(cpu, &desc, seg_idx);\n+ base = x86_segment_base(&desc);\n mode = cpu_mode(cpu);\n \n switch (mode) {\n@@ -116,21 +104,21 @@ static int linearize(CPUState *cpu,\n break;\n case PROTECTED_MODE:\n case REAL_MODE:\n- if (segment_type_ro(seg) && write) {\n+ if (segment_type_ro(desc) && write) {\n error_report(\"Cannot write to read-only segment\");\n return -1;\n }\n \n logical_addr_32b = logical_addr & 0xFFFFFFFF;\n- limit = segment_limit(seg);\n+ limit = x86_segment_limit(&desc);\n \n- if (segment_expands_down(seg)) {\n+ if (segment_expands_down(desc)) {\n if (logical_addr_32b >= limit) {\n error_report(\"Address exceeds limit (expands down)\");\n return -1;\n }\n \n- limit = segment_max_limit(seg);\n+ limit = segment_max_limit(desc);\n }\n \n if (logical_addr_32b > limit) {\n","prefixes":["PULL","13/19"]}