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Tsirkin" , Marcel Apfelbaum , Richard Henderson , Eduardo Habkost , Jason Wang , Marcelo Tosatti , qemu-block@nongnu.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org Subject: [PULL 01/15] i386/xen: Ignore VCPU_SSHOTTMR_future flag in set_singleshot_timer() Date: Tue, 7 Nov 2023 09:21:33 +0000 Message-ID: <20231107092149.404842-2-dwmw2@infradead.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231107092149.404842-1-dwmw2@infradead.org> References: <20231107092149.404842-1-dwmw2@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html From: David Woodhouse Upstream Xen now ignores this flag¹, since the only guest kernel ever to use it was buggy. ¹ https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=19c6cbd909 Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- target/i386/kvm/xen-emu.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index 75b2c557b9..1dc9ab0d91 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -1077,17 +1077,13 @@ static int vcpuop_stop_periodic_timer(CPUState *target) * Must always be called with xen_timers_lock held. */ static int do_set_singleshot_timer(CPUState *cs, uint64_t timeout_abs, - bool future, bool linux_wa) + bool linux_wa) { CPUX86State *env = &X86_CPU(cs)->env; int64_t now = kvm_get_current_ns(); int64_t qemu_now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); int64_t delta = timeout_abs - now; - if (future && timeout_abs < now) { - return -ETIME; - } - if (linux_wa && unlikely((int64_t)timeout_abs < 0 || (delta > 0 && (uint32_t)(delta >> 50) != 0))) { /* @@ -1129,9 +1125,13 @@ static int vcpuop_set_singleshot_timer(CPUState *cs, uint64_t arg) } QEMU_LOCK_GUARD(&X86_CPU(cs)->env.xen_timers_lock); - return do_set_singleshot_timer(cs, sst.timeout_abs_ns, - !!(sst.flags & VCPU_SSHOTTMR_future), - false); + + /* + * We ignore the VCPU_SSHOTTMR_future flag, just as Xen now does. + * The only guest that ever used it, got it wrong. + * https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=19c6cbd909 + */ + return do_set_singleshot_timer(cs, sst.timeout_abs_ns, false); } static int vcpuop_stop_singleshot_timer(CPUState *cs) @@ -1156,7 +1156,7 @@ static bool kvm_xen_hcall_set_timer_op(struct kvm_xen_exit *exit, X86CPU *cpu, err = vcpuop_stop_singleshot_timer(CPU(cpu)); } else { QEMU_LOCK_GUARD(&X86_CPU(cpu)->env.xen_timers_lock); - err = do_set_singleshot_timer(CPU(cpu), timeout, false, true); + err = do_set_singleshot_timer(CPU(cpu), timeout, true); } exit->u.hcall.result = err; return true; @@ -1844,7 +1844,7 @@ int kvm_put_xen_state(CPUState *cs) QEMU_LOCK_GUARD(&env->xen_timers_lock); if (env->xen_singleshot_timer_ns) { ret = do_set_singleshot_timer(cs, env->xen_singleshot_timer_ns, - false, false); + false); if (ret < 0) { return ret; }