From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [RFC 4/6] KVM: arm/arm64: enable irqchip routing Date: Thu, 18 Jun 2015 20:00:39 +0200 Message-ID: <55830747.7070101@linaro.org> References: <1434649258-27065-1-git-send-email-eric.auger@linaro.org> <1434649258-27065-5-git-send-email-eric.auger@linaro.org> <558305A2.8020206@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <558305A2.8020206@arm.com> Sender: kvm-owner@vger.kernel.org To: Marc Zyngier , "eric.auger@st.com" , "christoffer.dall@linaro.org" , Andre Przywara , "p.fedin@samsung.com" , "kvmarm@lists.cs.columbia.edu" , "kvm@vger.kernel.org" Cc: "patches@linaro.org" List-Id: kvmarm@lists.cs.columbia.edu Hi Marc, On 06/18/2015 07:53 PM, Marc Zyngier wrote: > Hi Eric, > > On 18/06/15 18:40, Eric Auger wrote: >> This patch adds compilation and link against irqchip. >> >> On ARM, irqchip routing is not really useful since there is >> a single irqchip. However main motivation behind using irqchip >> code is to enable MSI routing code. With the support of in-kernel >> GICv3 ITS emulation, it now seems to be a MUST HAVE requirement. >> >> Functions previously implemented in vgic.c and substitute >> to more complex irqchip implementation are removed: >> >> - kvm_send_userspace_msi >> - kvm_irq_map_chip_pin >> - kvm_set_irq >> - kvm_irq_map_gsi. >> >> They implemented a kernel default identity GSI routing. This is now >> replaced by user-side provided routing. >> >> Routing standard hooks are now implemented in vgic: >> - kvm_set_routing_entry >> - kvm_set_irq >> - kvm_set_msi >> >> Both HAVE_KVM_IRQCHIP and HAVE_KVM_IRQ_ROUTING are defined. >> KVM_CAP_IRQ_ROUTING is advertised and KVM_SET_GSI_ROUTING is allowed. >> >> MSI routing is not yet allowed. >> >> Signed-off-by: Eric Auger >> --- >> Documentation/virtual/kvm/api.txt | 11 ++++-- >> arch/arm/include/asm/kvm_host.h | 2 + >> arch/arm/kvm/Kconfig | 2 + >> arch/arm/kvm/Makefile | 2 +- >> arch/arm64/include/asm/kvm_host.h | 1 + >> arch/arm64/kvm/Kconfig | 2 + >> arch/arm64/kvm/Makefile | 2 +- >> include/kvm/arm_vgic.h | 9 ----- >> virt/kvm/arm/vgic.c | 78 ++++++++++++++++++++++++--------------- >> virt/kvm/irqchip.c | 2 + >> 10 files changed, 67 insertions(+), 44 deletions(-) >> >> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt >> index bcec91e..2bc96e1 100644 >> --- a/Documentation/virtual/kvm/api.txt >> +++ b/Documentation/virtual/kvm/api.txt >> @@ -1395,7 +1395,7 @@ KVM_ASSIGN_DEV_IRQ. Partial deassignment of host or guest IRQ is allowed. >> 4.52 KVM_SET_GSI_ROUTING >> >> Capability: KVM_CAP_IRQ_ROUTING >> -Architectures: x86 s390 >> +Architectures: x86 s390 arm arm64 >> Type: vm ioctl >> Parameters: struct kvm_irq_routing (in) >> Returns: 0 on success, -1 on error >> @@ -2310,9 +2310,12 @@ Note that closing the resamplefd is not sufficient to disable the >> irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment >> and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. >> >> -On ARM/ARM64, the gsi field in the kvm_irqfd struct specifies the Shared >> -Peripheral Interrupt (SPI) index, such that the GIC interrupt ID is >> -given by gsi + 32. >> +On ARM/ARM64, when GSI routing is not used, the gsi field in the >> +kvm_irqfd struct specifies the Shared Peripheral Interrupt (SPI) index, >> +such that the GIC interrupt ID is given by gsi + 32. When GSI routing is >> +setup: >> +- if irqchip routing: irqchip.pin + 32 is the SPI ID that is injected >> +- if MSI routing: the MSI data is used as interrupt ID (SPI or LPI). > > This feels just wrong. With GICv3, the MSI data is not the LPI at all. > It is an opaque value that gets translated into an LPI when combined > with the DeviceID. I agree with you. I need to rephrase that. In practice this is what should happen in the code since I use Andre's MSI injection routine which does the translation; except for GICv2 where last patch attempts to do direct gsi mapping from msi msg data! Thanks Eric > > Thanks, > > M. >