On 23/10/2019 13:39, Marc Zyngier wrote: > Hi Steven, > > On 2019-10-21 16:28, Steven Price wrote: >> This series add support for paravirtualized time for arm64 guests and >> KVM hosts following the specification in Arm's document DEN 0057A: >> >> https://developer.arm.com/docs/den0057/a >> >> It implements support for stolen time, allowing the guest to >> identify time when it is forcibly not executing. >> >> Note that Live Physical Time (LPT) which was previously part of the >> above specification has now been removed. >> >> Also available as a git tree: >> git://linux-arm.org/linux-sp.git stolen_time/v7 > > Can you please point me to userspace patches that I could apply to > kvmtool? I'd like to give this series a go as part of my normal testing. I don't have a proper patch yet, but the below is what I've been testing with (this breaks with kernels without PV-time). Steve ----8<---- >From 8f6540cfbe2842f3ee422c07fbd1f590534cc90a Mon Sep 17 00:00:00 2001 From: Steven Price <steven.price@xxxxxxx> Date: Thu, 8 Nov 2018 13:43:56 +0000 Subject: [PATCH kvmtool] ARM PV time support Signed-off-by: Steven Price <steven.price@xxxxxxx> --- Makefile | 2 +- arm/kvm-cpu.c | 4 ++++ arm/pvtime.c | 47 ++++++++++++++++++++++++++++++++++++++++ include/kvm/arm-pvtime.h | 6 +++++ 4 files changed, 58 insertions(+), 1 deletion(-) create mode 100644 arm/pvtime.c create mode 100644 include/kvm/arm-pvtime.h diff --git a/Makefile b/Makefile index 3862112..a79956b 100644 --- a/Makefile +++ b/Makefile @@ -158,7 +158,7 @@ endif # ARM OBJS_ARM_COMMON := arm/fdt.o arm/gic.o arm/gicv2m.o arm/ioport.o \ arm/kvm.o arm/kvm-cpu.o arm/pci.o arm/timer.o \ - arm/pmu.o + arm/pmu.o arm/pvtime.o HDRS_ARM_COMMON := arm/include ifeq ($(ARCH), arm) DEFINES += -DCONFIG_ARM diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c index 7780251..c903b05 100644 --- a/arm/kvm-cpu.c +++ b/arm/kvm-cpu.c @@ -1,5 +1,6 @@ #include "kvm/kvm.h" #include "kvm/kvm-cpu.h" +#include "kvm/arm-pvtime.h" static int debug_fd; @@ -122,6 +123,9 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id) vcpu->cpu_compatible = target->compatible; vcpu->is_running = true; + if (pvtime_vcpu_init(vcpu)) + die("Unable to initialise pvtime"); + return vcpu; } diff --git a/arm/pvtime.c b/arm/pvtime.c new file mode 100644 index 0000000..fc152d3 --- /dev/null +++ b/arm/pvtime.c @@ -0,0 +1,47 @@ +#include "kvm/kvm.h" +#include "kvm/kvm-cpu.h" +#include "kvm/arm-pvtime.h" + +#define PVTIME_BASE 0x10000000 + +#define KVM_ARM_VCPU_PVTIME_CTRL 2 +#define KVM_ARM_VCPU_PVTIME_IPA 0 + +static int pvtime_init(struct kvm *kvm) +{ + char *mem; + int size = ALIGN(64 * kvm->cfg.nrcpus, PAGE_SIZE); + + mem = mmap(NULL, size, PROT_RW, MAP_ANON_NORESERVE, -1, 0); + if (mem == MAP_FAILED) + return -ENOMEM; + + if (kvm__register_dev_mem(kvm, PVTIME_BASE, size, mem)) + return -EINVAL; + + return 0; +} + +base_init(pvtime_init); + +int pvtime_vcpu_init(struct kvm_cpu *vcpu) +{ + int err; + u64 st_paddr = PVTIME_BASE; + + st_paddr += vcpu->cpu_id * 64; + + struct kvm_device_attr st_base = { + .group = KVM_ARM_VCPU_PVTIME_CTRL, + .attr = KVM_ARM_VCPU_PVTIME_IPA, + .addr = (u64)&st_paddr + }; + + err = ioctl(vcpu->vcpu_fd, KVM_SET_DEVICE_ATTR, &st_base); + if (err) { + perror("ioctl st_base failed"); + return err; + } + + return 0; +} diff --git a/include/kvm/arm-pvtime.h b/include/kvm/arm-pvtime.h new file mode 100644 index 0000000..f5db286 --- /dev/null +++ b/include/kvm/arm-pvtime.h @@ -0,0 +1,6 @@ +#ifndef ARM_PVTIME_H +#define ARM_PVTIME_H + +int pvtime_vcpu_init(struct kvm_cpu *vcpu); + +#endif -- 2.20.1
