Mostly i386 patches for QEMU 11.0 soft freeze

[PULL 005/102] target/i386/emulate: rework string_rep emulation

Paolo Bonzini posted 102 patches 1 month, 1 week ago

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Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Alexander Graf <graf@amazon.com>, Pedro Barbuda <pbarbuda@microsoft.com>, Mohamed Mediouni <mohamed@unpredictable.fr>, Gerd Hoffmann <kraxel@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Pierrick Bouvier <pierrick.bouvier@linaro.org>, Dorjoy Chowdhury <dorjoychy111@gmail.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Zhao Liu <zhao1.liu@intel.com>, "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>, "Michael S. Tsirkin" <mst@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Bernhard Beschow <shentey@gmail.com>, Alex Williamson <alex@shazbot.org>, "Cédric Le Goater" <clg@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Peter Xu <peterx@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, John Snow <jsnow@redhat.com>, Cleber Rosa <crosa@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Manos Pitsidianakis <manos.pitsidianakis@linaro.org>, "Alex Bennée" <alex.bennee@linaro.org>, Thomas Huth <thuth@redhat.com>, Ani Sinha <anisinha@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Cameron Esfahani <dirty@apple.com>, Roman Bolshakov <rbolshakov@ddn.com>, Phil Dennis-Jordan <phil@philjordan.eu>, Wei Liu <wei.liu@kernel.org>, Marcelo Tosatti <mtosatti@redhat.com>, David Woodhouse <dwmw2@infradead.org>, Paul Durrant <paul@xen.org>, Magnus Kulke <magnus.kulke@linux.microsoft.com>, Fabiano Rosas <farosas@suse.de>, Laurent Vivier <lvivier@redhat.com>

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[PULL 005/102] target/i386/emulate: rework string_rep emulation

Posted by Paolo Bonzini 1 month, 1 week ago

From: Mohamed Mediouni <mohamed@unpredictable.fr>

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
Link: https://lore.kernel.org/r/20260223233950.96076-5-mohamed@unpredictable.fr
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/emulate/x86_emu.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/target/i386/emulate/x86_emu.c b/target/i386/emulate/x86_emu.c
index 4409f7bc134..bf96fe06b45 100644
--- a/target/i386/emulate/x86_emu.c
+++ b/target/i386/emulate/x86_emu.c
@@ -466,18 +466,25 @@ static inline void string_increment_reg(CPUX86State *env, int reg,
     write_reg(env, reg, val, decode->addressing_size);
 }
 
+static inline int get_ZF(CPUX86State *env) {
+    return env->cc_dst ? 0 : CC_Z;
+}
+
 static inline void string_rep(CPUX86State *env, struct x86_decode *decode,
                               void (*func)(CPUX86State *env,
                                            struct x86_decode *ins), int rep)
 {
     target_ulong rcx = read_reg(env, R_ECX, decode->addressing_size);
-    while (rcx--) {
+
+    while (rcx != 0) {
+        bool is_cmps_or_scas = decode->cmd == X86_DECODE_CMD_CMPS || decode->cmd == X86_DECODE_CMD_SCAS;
         func(env, decode);
+        rcx--;
         write_reg(env, R_ECX, rcx, decode->addressing_size);
-        if ((PREFIX_REP == rep) && !env->cc_dst) {
+        if ((PREFIX_REP == rep) && !get_ZF(env) && is_cmps_or_scas) {
             break;
         }
-        if ((PREFIX_REPN == rep) && env->cc_dst) {
+        if ((PREFIX_REPN == rep) && get_ZF(env)&& is_cmps_or_scas) {
             break;
         }
     }
-- 
2.53.0