From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=45192 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pjs42-0007y2-U5 for qemu-devel@nongnu.org; Mon, 31 Jan 2011 06:36:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Pjs41-0004Wz-LW for qemu-devel@nongnu.org; Mon, 31 Jan 2011 06:36:58 -0500 Received: from thoth.sbs.de ([192.35.17.2]:24445) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Pjs41-0004Wp-93 for qemu-devel@nongnu.org; Mon, 31 Jan 2011 06:36:57 -0500 Message-ID: <4D469ED6.9050805@siemens.com> Date: Mon, 31 Jan 2011 12:36:54 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <8db93a26b3cbb67e309d05600811dd6a37b34433.1296133797.git.jan.kiszka@siemens.com> <4D468A24.4080800@redhat.com> In-Reply-To: <4D468A24.4080800@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH 17/22] kvm: Move irqchip event processing out of inner loop List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Marcelo Tosatti , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" On 2011-01-31 11:08, Avi Kivity wrote: > On 01/27/2011 03:10 PM, Jan Kiszka wrote: >> Align with qemu-kvm and prepare for IO exit fix: There is no need to run >> kvm_arch_process_irqchip_events in the inner VCPU loop. Any state change >> this service processes will first cause an exit from kvm_cpu_exec >> anyway. And we will have to reenter the kernel on IO exits >> unconditionally, something that the current logic prevents. >> >> Signed-off-by: Jan Kiszka >> --- >> kvm-all.c | 11 ++++++----- >> 1 files changed, 6 insertions(+), 5 deletions(-) >> >> diff --git a/kvm-all.c b/kvm-all.c >> index 5bfa8c0..46ecc1c 100644 >> --- a/kvm-all.c >> +++ b/kvm-all.c >> @@ -892,6 +892,12 @@ int kvm_cpu_exec(CPUState *env) >> >> DPRINTF("kvm_cpu_exec()\n"); >> >> + if (kvm_arch_process_irqchip_events(env)) { >> + env->exit_request = 0; >> + env->exception_index = EXCP_HLT; >> + return 0; >> + } >> + >> do { >> #ifndef CONFIG_IOTHREAD >> if (env->exit_request) { >> @@ -901,11 +907,6 @@ int kvm_cpu_exec(CPUState *env) >> } > > We check for ->exit_request here > >> #endif >> >> - if (kvm_arch_process_irqchip_events(env)) { >> - ret = 0; >> - break; >> - } >> - > > But this checks for ->interrupt_request. What ensures that we exit when > ->interrupt_request is set? Good question, need to check again. But if that turns out to be an issue, qemu-kvm would be broken as well. I'm just aligning the code here. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux