From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Murzin Subject: Re: [PATCH v3 5/8] KVM: arm: vgic: Support 64-bit data manipulation on 32-bit host systems Date: Mon, 12 Sep 2016 10:25:24 +0100 Message-ID: <57D67484.3030604@arm.com> References: <1473350810-10857-1-git-send-email-vladimir.murzin@arm.com> <1473350810-10857-6-git-send-email-vladimir.murzin@arm.com> <57D2E96B.70909@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 3341D40F9B for ; Mon, 12 Sep 2016 05:16:48 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4B1DEi72CbdX for ; Mon, 12 Sep 2016 05:16:46 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 79BFE40C9A for ; Mon, 12 Sep 2016 05:16:46 -0400 (EDT) In-Reply-To: <57D2E96B.70909@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Marc Zyngier , kvmarm@lists.cs.columbia.edu Cc: andre.przywara@arm.com, linux-arm-kernel@lists.infradead.org List-Id: kvmarm@lists.cs.columbia.edu On 09/09/16 17:55, Marc Zyngier wrote: > On 08/09/16 17:06, Vladimir Murzin wrote: >> We have couple of 64-bit registers defined in GICv3 architecture, so >> unsigned long accesses to these registers will only access a single >> 32-bit part of that regitser. On the other hand these registers can't >> be accessed as 64-bit with a single instruction like ldrd/strd or >> ldmia/stmia if we run a 32-bit host because KVM does not support >> access to MMIO space done by these instructions. >> >> It means that a 32-bit guest accesses these registers in 32-bit >> chunks, so the only thing we need to do is to ensure that >> extract_bytes() always takes 64-bit data. >> >> Since we are here fix couple of other width related issues catched by >> gcc >> >> Signed-off-by: Vladimir Murzin >> --- >> virt/kvm/arm/vgic/vgic-mmio-v3.c | 6 +++--- >> virt/kvm/arm/vgic/vgic-mmio.h | 2 +- >> 2 files changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> index acbe691..0d3c76a 100644 >> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c >> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> @@ -23,7 +23,7 @@ >> #include "vgic-mmio.h" >> >> /* extract @num bytes at @offset bytes offset in data */ >> -unsigned long extract_bytes(unsigned long data, unsigned int offset, >> +unsigned long extract_bytes(u64 data, unsigned int offset, >> unsigned int num) >> { >> return (data >> (offset * 8)) & GENMASK_ULL(num * 8 - 1, 0); >> @@ -181,7 +181,7 @@ static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu, >> int target_vcpu_id = vcpu->vcpu_id; >> u64 value; >> >> - value = (mpidr & GENMASK(23, 0)) << 32; >> + value = (u64)(mpidr & GENMASK(23, 0)) << 32; >> value |= ((target_vcpu_id & 0xffff) << 8); >> if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1) >> value |= GICR_TYPER_LAST; >> @@ -611,7 +611,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg) >> bool broadcast; >> >> sgi = (reg & ICC_SGI1R_SGI_ID_MASK) >> ICC_SGI1R_SGI_ID_SHIFT; >> - broadcast = reg & BIT(ICC_SGI1R_IRQ_ROUTING_MODE_BIT); >> + broadcast = reg & BIT_ULL(ICC_SGI1R_IRQ_ROUTING_MODE_BIT); >> target_cpus = (reg & ICC_SGI1R_TARGET_LIST_MASK) >> ICC_SGI1R_TARGET_LIST_SHIFT; >> mpidr = SGI_AFFINITY_LEVEL(reg, 3); >> mpidr |= SGI_AFFINITY_LEVEL(reg, 2); >> diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h >> index 0b3ecf9..80f92ce 100644 >> --- a/virt/kvm/arm/vgic/vgic-mmio.h >> +++ b/virt/kvm/arm/vgic/vgic-mmio.h >> @@ -96,7 +96,7 @@ unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len); >> void vgic_data_host_to_mmio_bus(void *buf, unsigned int len, >> unsigned long data); >> >> -unsigned long extract_bytes(unsigned long data, unsigned int offset, >> +unsigned long extract_bytes(u64 data, unsigned int offset, >> unsigned int num); >> >> u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len, >> > > My personal preference would be to split this in two patches. One that > changes extract_bytes to work on 64bit quantities, and another one that > addresses the 64bit issues. Not a big deal though. > Anyway I have to resend, so I'll split it per your preference ;) > Acked-by: Marc Zyngier > Thanks! Vladimir > Thanks, > > M. >