From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Wed, 17 Jun 2015 13:48:31 +0100 Subject: [PATCH v3 06/10] arm: simplify MMIO dispatching In-Reply-To: <1434540121-21283-7-git-send-email-andre.przywara@arm.com> References: <1434540121-21283-1-git-send-email-andre.przywara@arm.com> <1434540121-21283-7-git-send-email-andre.przywara@arm.com> Message-ID: <55816C9F.1090500@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 17/06/15 12:21, Andre Przywara wrote: > Currently we separate any incoming MMIO request into one of the ARM > memory map regions and take care to spare the GIC. > It turns out that this is unnecessary, as we only have one special > region (the IO port area in the first 64 KByte). The MMIO rbtree > takes care about unhandled MMIO ranges, so we can simply drop all the > special range checking (except that for the IO range) in > kvm_cpu__emulate_mmio(). > As the GIC is handled in the kernel, a GIC MMIO access should never > reach userland (and we don't know what to do with it anyway). > This lets us delete some more code and simplifies future extensions > (like expanding the GIC regions). > To be in line with the other architectures, move the now simpler > code into a header file. > > Signed-off-by: Andre Przywara > --- > arm/include/arm-common/kvm-arch.h | 12 ------------ > arm/include/arm-common/kvm-cpu-arch.h | 14 ++++++++++++-- > arm/kvm-cpu.c | 16 ---------------- > 3 files changed, 12 insertions(+), 30 deletions(-) > > diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h > index 082131d..90d6733 100644 > --- a/arm/include/arm-common/kvm-arch.h > +++ b/arm/include/arm-common/kvm-arch.h > @@ -45,18 +45,6 @@ static inline bool arm_addr_in_ioport_region(u64 phys_addr) > return phys_addr >= KVM_IOPORT_AREA && phys_addr < limit; > } > > -static inline bool arm_addr_in_virtio_mmio_region(u64 phys_addr) > -{ > - u64 limit = KVM_VIRTIO_MMIO_AREA + ARM_VIRTIO_MMIO_SIZE; > - return phys_addr >= KVM_VIRTIO_MMIO_AREA && phys_addr < limit; > -} > - > -static inline bool arm_addr_in_pci_region(u64 phys_addr) > -{ > - u64 limit = KVM_PCI_CFG_AREA + ARM_PCI_CFG_SIZE + ARM_PCI_MMIO_SIZE; > - return phys_addr >= KVM_PCI_CFG_AREA && phys_addr < limit; > -} > - > struct kvm_arch { > /* > * We may have to align the guest memory for virtio, so keep the > diff --git a/arm/include/arm-common/kvm-cpu-arch.h b/arm/include/arm-common/kvm-cpu-arch.h > index 36c7872..329979a 100644 > --- a/arm/include/arm-common/kvm-cpu-arch.h > +++ b/arm/include/arm-common/kvm-cpu-arch.h > @@ -44,8 +44,18 @@ static inline bool kvm_cpu__emulate_io(struct kvm_cpu *vcpu, u16 port, void *dat > return false; > } > > -bool kvm_cpu__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, u8 *data, > - u32 len, u8 is_write); > +static inline bool kvm_cpu__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, > + u8 *data, u32 len, u8 is_write) > +{ > + if (arm_addr_in_ioport_region(phys_addr)) { > + int direction = is_write ? KVM_EXIT_IO_OUT : KVM_EXIT_IO_IN; > + u16 port = (phys_addr - KVM_IOPORT_AREA) & USHRT_MAX; > + > + return kvm__emulate_io(vcpu, port, data, direction, len, 1); > + } > + > + return kvm__emulate_mmio(vcpu, phys_addr, data, len, is_write); > +} > > unsigned long kvm_cpu__get_vcpu_mpidr(struct kvm_cpu *vcpu); > > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index ab08815..7780251 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -139,22 +139,6 @@ bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) > return false; > } > > -bool kvm_cpu__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, u8 *data, > - u32 len, u8 is_write) > -{ > - if (arm_addr_in_virtio_mmio_region(phys_addr)) { > - return kvm__emulate_mmio(vcpu, phys_addr, data, len, is_write); > - } else if (arm_addr_in_ioport_region(phys_addr)) { > - int direction = is_write ? KVM_EXIT_IO_OUT : KVM_EXIT_IO_IN; > - u16 port = (phys_addr - KVM_IOPORT_AREA) & USHRT_MAX; > - return kvm__emulate_io(vcpu, port, data, direction, len, 1); > - } else if (arm_addr_in_pci_region(phys_addr)) { > - return kvm__emulate_mmio(vcpu, phys_addr, data, len, is_write); > - } Can you explain why this arm_addr_in_pci_region(phys_addr) check has disappeared in your updated version on this function? It may be a non issue, but I'd very much like to understand. Thanks, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v3 06/10] arm: simplify MMIO dispatching Date: Wed, 17 Jun 2015 13:48:31 +0100 Message-ID: <55816C9F.1090500@arm.com> References: <1434540121-21283-1-git-send-email-andre.przywara@arm.com> <1434540121-21283-7-git-send-email-andre.przywara@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1434540121-21283-7-git-send-email-andre.przywara@arm.com> Sender: kvm-owner@vger.kernel.org To: Andre Przywara , Will Deacon Cc: "penberg@kernel.org" , "kvmarm@lists.cs.columbia.edu" , "kvm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: kvmarm@lists.cs.columbia.edu On 17/06/15 12:21, Andre Przywara wrote: > Currently we separate any incoming MMIO request into one of the ARM > memory map regions and take care to spare the GIC. > It turns out that this is unnecessary, as we only have one special > region (the IO port area in the first 64 KByte). The MMIO rbtree > takes care about unhandled MMIO ranges, so we can simply drop all the > special range checking (except that for the IO range) in > kvm_cpu__emulate_mmio(). > As the GIC is handled in the kernel, a GIC MMIO access should never > reach userland (and we don't know what to do with it anyway). > This lets us delete some more code and simplifies future extensions > (like expanding the GIC regions). > To be in line with the other architectures, move the now simpler > code into a header file. > > Signed-off-by: Andre Przywara > --- > arm/include/arm-common/kvm-arch.h | 12 ------------ > arm/include/arm-common/kvm-cpu-arch.h | 14 ++++++++++++-- > arm/kvm-cpu.c | 16 ---------------- > 3 files changed, 12 insertions(+), 30 deletions(-) > > diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h > index 082131d..90d6733 100644 > --- a/arm/include/arm-common/kvm-arch.h > +++ b/arm/include/arm-common/kvm-arch.h > @@ -45,18 +45,6 @@ static inline bool arm_addr_in_ioport_region(u64 phys_addr) > return phys_addr >= KVM_IOPORT_AREA && phys_addr < limit; > } > > -static inline bool arm_addr_in_virtio_mmio_region(u64 phys_addr) > -{ > - u64 limit = KVM_VIRTIO_MMIO_AREA + ARM_VIRTIO_MMIO_SIZE; > - return phys_addr >= KVM_VIRTIO_MMIO_AREA && phys_addr < limit; > -} > - > -static inline bool arm_addr_in_pci_region(u64 phys_addr) > -{ > - u64 limit = KVM_PCI_CFG_AREA + ARM_PCI_CFG_SIZE + ARM_PCI_MMIO_SIZE; > - return phys_addr >= KVM_PCI_CFG_AREA && phys_addr < limit; > -} > - > struct kvm_arch { > /* > * We may have to align the guest memory for virtio, so keep the > diff --git a/arm/include/arm-common/kvm-cpu-arch.h b/arm/include/arm-common/kvm-cpu-arch.h > index 36c7872..329979a 100644 > --- a/arm/include/arm-common/kvm-cpu-arch.h > +++ b/arm/include/arm-common/kvm-cpu-arch.h > @@ -44,8 +44,18 @@ static inline bool kvm_cpu__emulate_io(struct kvm_cpu *vcpu, u16 port, void *dat > return false; > } > > -bool kvm_cpu__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, u8 *data, > - u32 len, u8 is_write); > +static inline bool kvm_cpu__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, > + u8 *data, u32 len, u8 is_write) > +{ > + if (arm_addr_in_ioport_region(phys_addr)) { > + int direction = is_write ? KVM_EXIT_IO_OUT : KVM_EXIT_IO_IN; > + u16 port = (phys_addr - KVM_IOPORT_AREA) & USHRT_MAX; > + > + return kvm__emulate_io(vcpu, port, data, direction, len, 1); > + } > + > + return kvm__emulate_mmio(vcpu, phys_addr, data, len, is_write); > +} > > unsigned long kvm_cpu__get_vcpu_mpidr(struct kvm_cpu *vcpu); > > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index ab08815..7780251 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -139,22 +139,6 @@ bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) > return false; > } > > -bool kvm_cpu__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, u8 *data, > - u32 len, u8 is_write) > -{ > - if (arm_addr_in_virtio_mmio_region(phys_addr)) { > - return kvm__emulate_mmio(vcpu, phys_addr, data, len, is_write); > - } else if (arm_addr_in_ioport_region(phys_addr)) { > - int direction = is_write ? KVM_EXIT_IO_OUT : KVM_EXIT_IO_IN; > - u16 port = (phys_addr - KVM_IOPORT_AREA) & USHRT_MAX; > - return kvm__emulate_io(vcpu, port, data, direction, len, 1); > - } else if (arm_addr_in_pci_region(phys_addr)) { > - return kvm__emulate_mmio(vcpu, phys_addr, data, len, is_write); > - } Can you explain why this arm_addr_in_pci_region(phys_addr) check has disappeared in your updated version on this function? It may be a non issue, but I'd very much like to understand. Thanks, M. -- Jazz is not dead. It just smells funny...