From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: [PATCH v7 01/12] xen/arm: no need to set HCR_VI when using the vgic to inject irqs Date: Tue, 8 Apr 2014 16:12:38 +0100 Message-ID: <1396969969-18973-1-git-send-email-stefano.stabellini@eu.citrix.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xensource.com Cc: julien.grall@citrix.com, Ian.Campbell@citrix.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org HCR_VI forces the guest to resume execution in IRQ mode and can actually cause spurious interrupt injections. The GIC is capable of injecting interrupts into the guest and causing it to switch to IRQ mode automatically, without any need for the hypervisor to set HCR_VI manually. See ARM ARM B1.8.11 and chapter 5.4 of the Generic Interrupt Controller Architecture Specification. Signed-off-by: Stefano Stabellini Acked-by: Julien Grall Acked-by: Ian Campbell --- Changes in v4: - improve commit message. --- xen/arch/arm/gic.c | 20 -------------------- 1 file changed, 20 deletions(-) diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index 91a2982..b388ef3 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -726,22 +726,6 @@ void gic_clear_pending_irqs(struct vcpu *v) spin_unlock_irqrestore(&gic.lock, flags); } -static void gic_inject_irq_start(void) -{ - register_t hcr = READ_SYSREG(HCR_EL2); - WRITE_SYSREG(hcr | HCR_VI, HCR_EL2); - isb(); -} - -static void gic_inject_irq_stop(void) -{ - register_t hcr = READ_SYSREG(HCR_EL2); - if (hcr & HCR_VI) { - WRITE_SYSREG(hcr & ~HCR_VI, HCR_EL2); - isb(); - } -} - int gic_events_need_delivery(void) { return (!list_empty(¤t->arch.vgic.lr_pending) || @@ -754,10 +738,6 @@ void gic_inject(void) vgic_vcpu_inject_irq(current, current->domain->arch.evtchn_irq, 1); gic_restore_pending_irqs(current); - if (!gic_events_need_delivery()) - gic_inject_irq_stop(); - else - gic_inject_irq_start(); } int gic_route_irq_to_guest(struct domain *d, const struct dt_irq *irq, -- 1.7.10.4