From patchwork Wed Oct 25 14:50:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 13436349 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8ADF1C07545 for ; Wed, 25 Oct 2023 14:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344384AbjJYOvt (ORCPT ); Wed, 25 Oct 2023 10:51:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344522AbjJYOvd (ORCPT ); Wed, 25 Oct 2023 10:51:33 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3B9010FF for ; Wed, 25 Oct 2023 07:51:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description; bh=whwrxQfu34eIg/PcGjcBAI/B4Oo/UALoBhuUlK3a190=; b=KDzGOyRparAnnjvPQuEd8zIi5K k7eb8lLOjHiB0WgXqvHuzQDwCGSF8SeNp3WXmidEbK2bWXOc8w6x3TD6K+UXDO4sPnW2qMxW/v5SM JkSb1Z2JTnWnr0HgbFIP0bx5OGzSEiK94Vb17zrb+YHVm0KZ7bymHP1u6UIhnhK+Bc6wUnU6y7Tcd QiEF0/VJRFk98yveKudVwc1RUon2pG3PxUld5/P+sDKlYT/AT53ZbUp+UowXdbZhIXvkNmCB2PEB1 nhKcb/KtHS5HnBx5aIdzj2GaTnYdKhVRfmjK8CnHDLlElncrHUR+DaNttogg600wZhp3rq1/l+3G0 urtNKg8g==; Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qvfDZ-00GPLy-00; Wed, 25 Oct 2023 14:50:52 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qvfDY-002dER-0t; Wed, 25 Oct 2023 15:50:44 +0100 From: David Woodhouse To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , Stefano Stabellini , Anthony Perard , Paul Durrant , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , Paolo Bonzini , "Michael S. Tsirkin" , Marcel Apfelbaum , Richard Henderson , Eduardo Habkost , Jason Wang , Marcelo Tosatti , qemu-block@nongnu.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, Bernhard Beschow , Joel Upham Subject: [PATCH v3 08/28] i386/xen: Ignore VCPU_SSHOTTMR_future flag in set_singleshot_timer() Date: Wed, 25 Oct 2023 15:50:22 +0100 Message-Id: <20231025145042.627381-9-dwmw2@infradead.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231025145042.627381-1-dwmw2@infradead.org> References: <20231025145042.627381-1-dwmw2@infradead.org> MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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 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; }