Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753701AbaGONlF (ORCPT ); Tue, 15 Jul 2014 09:41:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15365 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753565AbaGONlA (ORCPT ); Tue, 15 Jul 2014 09:41:00 -0400 From: Vitaly Kuznetsov To: xen-devel@lists.xenproject.org Cc: Konrad Rzeszutek Wilk , Boris Ostrovsky , David Vrabel , Stefano Stabellini , Andrew Jones , linux-kernel@vger.kernel.org Subject: [PATCH RFC 4/4] xen/pvhvm: Make MSI IRQs work after kexec Date: Tue, 15 Jul 2014 15:40:40 +0200 Message-Id: <1405431640-649-5-git-send-email-vkuznets@redhat.com> In-Reply-To: <1405431640-649-1-git-send-email-vkuznets@redhat.com> References: <1405431640-649-1-git-send-email-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When kexec was peformed MSI IRQs for passthrough-ed devices were already mapped and we see non-zero pirq extracted from MSI msg. xen_irq_from_pirq() fails as we have no IRQ mapping information for that. Requesting for new mapping with __write_msi_msg() does not result in MSI IRQ being remapped so we don't recieve these IRQs. RFC: I wasn't able to understand why commit af42b8d1 which introduced xen_irq_from_pirq() check in xen_hvm_setup_msi_irqs() is checking that instead of checking pirq > 0 as if the mapping was already done (and we have pirq>0 here) we don't need to request for a new pirq. We're loosing existing PIRQ and I'm also not sure when __write_msi_msg() with new PIRQ will result in new mapping. Signed-off-by: Vitaly Kuznetsov --- arch/x86/pci/xen.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 905956f..685e8f1 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -231,8 +231,7 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) __read_msi_msg(msidesc, &msg); pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) | ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff); - if (msg.data != XEN_PIRQ_MSI_DATA || - xen_irq_from_pirq(pirq) < 0) { + if (msg.data != XEN_PIRQ_MSI_DATA || pirq <= 0) { pirq = xen_allocate_pirq_msi(dev, msidesc); if (pirq < 0) { irq = -ENODEV; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/