On Tue, May 10, 2016 at 02:42:02PM +0100, Marc Zyngier wrote: > On 10/05/16 14:30, Christoffer Dall wrote: > > On Fri, May 06, 2016 at 11:45:31AM +0100, Andre Przywara wrote: > >> From: Marc Zyngier <marc.zyngier@xxxxxxx> > >> > >> Processing maintenance interrupts and accessing the list registers > >> are dependent on the host's GIC version. > >> Introduce vgic-v2.c to contain GICv2 specific functions. > >> Implement the GICv2 specific code for syncing the emulation state > >> into the VGIC registers. > >> > >> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > >> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> > >> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> > >> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> > >> --- > >> Changelog RFC..v1: > >> - remove explicit LR_STATE clearing on maintenance interrupt handling > >> - improve documentation for vgic_v2_populate_lr() > >> - remove WARN_ON on non-edge IRQs in maintenance interrupts > >> - simplify multi-CPU source SGI handling > >> > >> Changelog v1 .. v2: > >> - inject the IRQ priority into the list register > >> > >> Changelog v2 .. v3: > >> - cleanup diff containing rebase artifacts > >> > >> include/linux/irqchip/arm-gic.h | 1 + > >> virt/kvm/arm/vgic/vgic-v2.c | 178 ++++++++++++++++++++++++++++++++++++++++ > >> virt/kvm/arm/vgic/vgic.c | 6 ++ > >> virt/kvm/arm/vgic/vgic.h | 6 ++ > >> 4 files changed, 191 insertions(+) > >> create mode 100644 virt/kvm/arm/vgic/vgic-v2.c > >> > >> diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h > >> index 9c94026..be0d26f 100644 > >> --- a/include/linux/irqchip/arm-gic.h > >> +++ b/include/linux/irqchip/arm-gic.h > >> @@ -76,6 +76,7 @@ > >> #define GICH_LR_VIRTUALID (0x3ff << 0) > >> #define GICH_LR_PHYSID_CPUID_SHIFT (10) > >> #define GICH_LR_PHYSID_CPUID (0x3ff << GICH_LR_PHYSID_CPUID_SHIFT) > >> +#define GICH_LR_PRIORITY_SHIFT 23 > >> #define GICH_LR_STATE (3 << 28) > >> #define GICH_LR_PENDING_BIT (1 << 28) > >> #define GICH_LR_ACTIVE_BIT (1 << 29) > >> diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c > >> new file mode 100644 > >> index 0000000..4cee616 > >> --- /dev/null > >> +++ b/virt/kvm/arm/vgic/vgic-v2.c > >> @@ -0,0 +1,178 @@ > >> +/* > >> + * Copyright (C) 2015, 2016 ARM Ltd. > >> + * > >> + * This program is free software; you can redistribute it and/or modify > >> + * it under the terms of the GNU General Public License version 2 as > >> + * published by the Free Software Foundation. > >> + * > >> + * This program is distributed in the hope that it will be useful, > >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > >> + * GNU General Public License for more details. > >> + * > >> + * You should have received a copy of the GNU General Public License > >> + * along with this program. If not, see <http://www.gnu.org/licenses/>. > >> + */ > >> + > >> +#include <linux/irqchip/arm-gic.h> > >> +#include <linux/kvm.h> > >> +#include <linux/kvm_host.h> > >> + > >> +#include "vgic.h" > >> + > >> +/* > >> + * Call this function to convert a u64 value to an unsigned long * bitmask > >> + * in a way that works on both 32-bit and 64-bit LE and BE platforms. > >> + * > >> + * Warning: Calling this function may modify *val. > >> + */ > >> +static unsigned long *u64_to_bitmask(u64 *val) > >> +{ > >> +#if defined(CONFIG_CPU_BIG_ENDIAN) && BITS_PER_LONG == 32 > >> + *val = (*val >> 32) | (*val << 32); > >> +#endif > >> + return (unsigned long *)val; > >> +} > >> + > >> +void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu) > >> +{ > >> + struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2; > >> + > >> + if (cpuif->vgic_misr & GICH_MISR_EOI) { > >> + u64 eisr = cpuif->vgic_eisr; > >> + unsigned long *eisr_bmap = u64_to_bitmask(&eisr); > >> + int lr; > >> + > >> + for_each_set_bit(lr, eisr_bmap, kvm_vgic_global_state.nr_lr) { > >> + u32 intid = cpuif->vgic_lr[lr] & GICH_LR_VIRTUALID; > >> + > >> + WARN_ON(cpuif->vgic_lr[lr] & GICH_LR_STATE); > >> + > >> + kvm_notify_acked_irq(vcpu->kvm, 0, > >> + intid - VGIC_NR_PRIVATE_IRQS); > >> + > > > > why do we need to do this? I cannot find any consumers of this info > > after we've left the hyp code. > > I believe that's for vhost and irqfd. Or am I misreading your question? > I meant the setting of the bits in vgic_elrsr (sorry, badly placed comment)... > > Also, I think I offered a comment about why we would potentially need > > this in the first place. This is the famous race where hardware doesn't > > guarantee consistency between the MISR and ELRSR right? > > That's the one (except it is between EISR and ELRSR). I don't have your > initial comment at hand, but would something like the following do? > > /* > * The maintenance interrupt may not have had a > * chance to update ELRSR, so let's mark the LRs > * presents in EISR as empty. > */ > > > >> + cpuif->vgic_elrsr |= 1ULL << lr; so, why are we doing this? > >> + } > >> + } > > Thanks, > > M. > -- > Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
