From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6AA20CAC589 for ; Mon, 8 Sep 2025 21:12:23 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1115556.1462223 (Exim 4.92) (envelope-from ) id 1uvj9q-0003IR-1W; Mon, 08 Sep 2025 21:12:14 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1115556.1462223; Mon, 08 Sep 2025 21:12:13 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uvj9o-0003Ct-Pk; Mon, 08 Sep 2025 21:12:12 +0000 Received: by outflank-mailman (input) for mailman id 1115556; Mon, 08 Sep 2025 21:12:09 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uvj9l-0002aN-RZ for xen-devel@lists.xenproject.org; Mon, 08 Sep 2025 21:12:09 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.96) (envelope-from ) id 1uvj9l-000FVX-2F; Mon, 08 Sep 2025 21:12:09 +0000 Received: from [19.12.91.86] (helo=localhost) by xenbits.xenproject.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uvj9l-000gNi-2T; Mon, 08 Sep 2025 21:12:09 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From; bh=QgoMqHbu0tUc+lVtvyYl2w5a013VrqpmgCwPwd2nRFw=; b=sOqZXpCXdQNe+SfB8ANsxd7Vn4 ZxrzEB4O/VMXSs0Fr3nr5FmWbheVLjFkqlmzUFrSF1+D0tmWM43cGV0CSvKydOw7dY9AbSw45y7M6 FsI9G9nOelJVlrFjztHRmbcjYGVEGob1snavNNwQppzgnhaWoUNvvV0i+b7LRE+TMm6E=; From: dmukhin@xen.org To: xen-devel@lists.xenproject.org Cc: andrew.cooper3@citrix.com, anthony.perard@vates.tech, jbeulich@suse.com, julien@xen.org, michal.orzel@amd.com, roger.pau@citrix.com, sstabellini@kernel.org, dmukhin@ford.com Subject: [PATCH v7 16/16] emul/ns16x50: implement IRQ emulation via vIOAPIC Date: Mon, 8 Sep 2025 14:11:49 -0700 Message-ID: <20250908211149.279143-17-dmukhin@ford.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250908211149.279143-1-dmukhin@ford.com> References: <20250908211149.279143-1-dmukhin@ford.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Denis Mukhin PVH domains use vIOAPIC, not vPIC and NS16550 emulates ISA IRQs which cannot be asserted on vIOAPIC. {map,unmap}_domain_pirq_emuirq() infrastructure is modified by adding new type of interrupt resources 'IRQ_EMU' which means 'emulated device IRQ' (similarly to IRQ_MSI_EMU). This is necessary to for IOAPIC emulation code to skip IRQ->PIRQ mapping (vioapic_hwdom_map_gsi()) when guest OS unmasks vIOAPIC pin corresponding to virtual device's IRQ. Also, hvm_gsi_eoi() is modified to trigger assertion in hvm_gsi_deassert() path for ISA IRQs. Signed-off-by: Denis Mukhin --- Changes since v6: - n/a --- xen/arch/x86/hvm/vioapic.c | 10 ++++++++++ xen/arch/x86/include/asm/irq.h | 6 ++++++ xen/common/emul/vuart/ns16x50.c | 28 ++++++++++++++++++++++++++-- xen/drivers/passthrough/x86/hvm.c | 11 ++++++++++- 4 files changed, 52 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/hvm/vioapic.c b/xen/arch/x86/hvm/vioapic.c index 7c725f9e471f..6314874b64f7 100644 --- a/xen/arch/x86/hvm/vioapic.c +++ b/xen/arch/x86/hvm/vioapic.c @@ -177,6 +177,16 @@ static int vioapic_hwdom_map_gsi(unsigned int gsi, unsigned int trig, ASSERT(is_hardware_domain(currd)); + /* + * Interrupt is claimed by one of the platform virtual devices (e.g. + * NS16550); do nothing. + */ + write_lock(&currd->event_lock); + ret = is_domain_emuirq_claimed(currd, gsi); + write_unlock(&currd->event_lock); + if ( ret ) + return 0; + /* Interrupt has been unmasked, bind it now. */ ret = mp_register_gsi(gsi, trig, pol); if ( ret == -EEXIST ) diff --git a/xen/arch/x86/include/asm/irq.h b/xen/arch/x86/include/asm/irq.h index 8bffec3bbfee..bdbe700274e9 100644 --- a/xen/arch/x86/include/asm/irq.h +++ b/xen/arch/x86/include/asm/irq.h @@ -168,6 +168,11 @@ void free_domain_pirqs(struct domain *d); int map_domain_emuirq_pirq(struct domain *d, int pirq, int emuirq); int unmap_domain_pirq_emuirq(struct domain *d, int pirq); +#define domain_emuirq_claim(d, irq) map_domain_emuirq_pirq(d, irq, IRQ_EMU) +#define domain_emuirq_unclaim(d, irq) unmap_domain_pirq_emuirq(d, irq) +#define is_domain_emuirq_claimed(d, irq) \ + (domain_pirq_to_emuirq(d, irq) != IRQ_UNBOUND) + /* Evacuate interrupts assigned to CPUs not present in the CPU online map. */ void fixup_irqs(void); void fixup_eoi(void); @@ -221,6 +226,7 @@ void cleanup_domain_irq_mapping(struct domain *d); #define IRQ_UNBOUND (-1) #define IRQ_PT (-2) #define IRQ_MSI_EMU (-3) +#define IRQ_EMU (-4) bool cpu_has_pending_apic_eoi(void); diff --git a/xen/common/emul/vuart/ns16x50.c b/xen/common/emul/vuart/ns16x50.c index 6bd58ba5540b..081d2639aa7a 100644 --- a/xen/common/emul/vuart/ns16x50.c +++ b/xen/common/emul/vuart/ns16x50.c @@ -299,7 +299,7 @@ static void ns16x50_irq_assert(const struct vuart_ns16x50 *vdev) if ( has_vpic(d) ) vector = hvm_isa_irq_assert(d, info->irq, vioapic_get_vector); else if ( has_vioapic(d) ) - /* TODO */ + vector = hvm_ioapic_assert(d, info->irq, false); else ASSERT_UNREACHABLE(); @@ -314,7 +314,7 @@ static void ns16x50_irq_deassert(const struct vuart_ns16x50 *vdev) if ( has_vpic(d) ) hvm_isa_irq_deassert(d, info->irq); else if ( has_vioapic(d) ) - /* TODO */ + hvm_ioapic_deassert(d, info->irq); else ASSERT_UNREACHABLE(); @@ -806,6 +806,17 @@ static int ns16x50_init(void *arg) return rc; } + /* Claim virtual IRQ */ + write_lock(&d->event_lock); + rc = domain_emuirq_claim(d, info->irq); + write_unlock(&d->event_lock); + if ( rc ) + { + ns16x50_err(info, "virtual IRQ#%d: cannot claim: %d\n", + info->irq, rc); + return rc; + } + /* NB: report 115200 baud rate. */ vdev->regs[NS16X50_REGS_NUM + UART_DLL] = divisor & UINT8_MAX; vdev->regs[NS16X50_REGS_NUM + UART_DLM] = (divisor >> 8) & UINT8_MAX; @@ -822,9 +833,22 @@ static int ns16x50_init(void *arg) static void cf_check ns16x50_deinit(void *arg) { struct vuart_ns16x50 *vdev = arg; + const struct vuart_info *info; + struct domain *d; + int rc; ASSERT(vdev); + d = vdev->owner; + info = vdev->info; + + write_lock(&d->event_lock); + rc = domain_emuirq_unclaim(d, info->irq); + write_unlock(&d->event_lock); + if ( rc ) + ns16x50_err(vdev, "virtual IRQ#%d: cannot unclaim: %d\n", + info->irq, rc); + spin_lock(&vdev->lock); ns16x50_fifo_tx_flush(vdev); spin_unlock(&vdev->lock); diff --git a/xen/drivers/passthrough/x86/hvm.c b/xen/drivers/passthrough/x86/hvm.c index a2ca7e0e570c..20641194561f 100644 --- a/xen/drivers/passthrough/x86/hvm.c +++ b/xen/drivers/passthrough/x86/hvm.c @@ -922,7 +922,16 @@ static void __hvm_dpci_eoi(struct domain *d, static void hvm_gsi_eoi(struct domain *d, unsigned int gsi) { - struct pirq *pirq = pirq_info(d, gsi); + struct pirq *pirq; + + /* Check if GSI is claimed by one of the virtual devices. */ + if ( is_domain_emuirq_claimed(d, gsi) ) + { + hvm_gsi_deassert(d, gsi); + return; + } + + pirq = pirq_info(d, gsi); /* Check if GSI is actually mapped. */ if ( !pirq_dpci(pirq) ) -- 2.51.0