Hi, On Mon, Mar 07, 2022 at 02:42:43PM +0000, Sebastian Ene wrote: > This patch adds support for stolen time by sharing a memory region > with the guest which will be used by the hypervisor to store the stolen > time information. Reserve a 64kb MMIO memory region after the RTC peripheral > to be used by pvtime. The exact format of the structure stored by the > hypervisor is described in the ARM DEN0057A document. > > Signed-off-by: Sebastian Ene <sebastianene@xxxxxxxxxx> > --- > Makefile | 1 + > arm/aarch64/arm-cpu.c | 2 +- > arm/aarch64/include/kvm/kvm-cpu-arch.h | 2 + > arm/aarch64/pvtime.c | 108 +++++++++++++++++++++++++ > arm/include/arm-common/kvm-arch.h | 6 +- > arm/kvm-cpu.c | 1 + > include/kvm/kvm-config.h | 1 + > 7 files changed, 119 insertions(+), 2 deletions(-) > create mode 100644 arm/aarch64/pvtime.c > > diff --git a/Makefile b/Makefile > index f251147..e9121dc 100644 > --- a/Makefile > +++ b/Makefile > @@ -182,6 +182,7 @@ ifeq ($(ARCH), arm64) > OBJS += arm/aarch64/arm-cpu.o > OBJS += arm/aarch64/kvm-cpu.o > OBJS += arm/aarch64/kvm.o > + OBJS += arm/aarch64/pvtime.o > ARCH_INCLUDE := $(HDRS_ARM_COMMON) > ARCH_INCLUDE += -Iarm/aarch64/include > > diff --git a/arm/aarch64/arm-cpu.c b/arm/aarch64/arm-cpu.c > index d7572b7..7e4a3c1 100644 > --- a/arm/aarch64/arm-cpu.c > +++ b/arm/aarch64/arm-cpu.c > @@ -22,7 +22,7 @@ static void generate_fdt_nodes(void *fdt, struct kvm *kvm) > static int arm_cpu__vcpu_init(struct kvm_cpu *vcpu) > { > vcpu->generate_fdt_nodes = generate_fdt_nodes; > - return 0; > + return kvm_cpu__setup_pvtime(vcpu); > } > > static struct kvm_arm_target target_generic_v8 = { > diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h > index 8dfb82e..35996dc 100644 > --- a/arm/aarch64/include/kvm/kvm-cpu-arch.h > +++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h > @@ -19,5 +19,7 @@ > > void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init); > int kvm_cpu__configure_features(struct kvm_cpu *vcpu); > +int kvm_cpu__setup_pvtime(struct kvm_cpu *vcpu); > +int kvm_cpu__teardown_pvtime(struct kvm *kvm); > > #endif /* KVM__KVM_CPU_ARCH_H */ > diff --git a/arm/aarch64/pvtime.c b/arm/aarch64/pvtime.c > new file mode 100644 > index 0000000..4db2e9f > --- /dev/null > +++ b/arm/aarch64/pvtime.c > @@ -0,0 +1,108 @@ > +#include "kvm/kvm.h" > +#include "kvm/kvm-cpu.h" > +#include "kvm/util.h" > + > +#include <linux/byteorder.h> > +#include <linux/types.h> > + > +#define ARM_PVTIME_STRUCT_SIZE (64) > + > +struct pvtime_data_priv { > + bool is_failed_cfg; > + void *usr_mem; > +}; > + > +static struct pvtime_data_priv pvtime_data = { > + .is_failed_cfg = true, > + .usr_mem = NULL > +}; > + > +static int pvtime__alloc_region(struct kvm *kvm) > +{ > + char *mem; > + int ret = 0; > + > + mem = mmap(NULL, ARM_PVTIME_BASE, PROT_RW, > + MAP_ANON_NORESERVE, -1, 0); > + if (mem == MAP_FAILED) > + return -errno; > + > + ret = kvm__register_ram(kvm, ARM_PVTIME_BASE, > + ARM_PVTIME_BASE, mem); > + if (ret) { > + munmap(mem, ARM_PVTIME_BASE); > + return ret; > + } > + > + pvtime_data.usr_mem = mem; > + return ret; > +} > + > +static int pvtime__teardown_region(struct kvm *kvm) > +{ > + if (pvtime_data.usr_mem == NULL) > + return 0; > + > + kvm__destroy_mem(kvm, ARM_PVTIME_BASE, > + ARM_PVTIME_BASE, pvtime_data.usr_mem); > + munmap(pvtime_data.usr_mem, ARM_PVTIME_BASE); > + pvtime_data.usr_mem = NULL; > + return 0; > +} > + > +int kvm_cpu__setup_pvtime(struct kvm_cpu *vcpu) > +{ > + int ret; > + bool has_stolen_time; > + u64 pvtime_guest_addr = ARM_PVTIME_BASE + vcpu->cpu_id * > + ARM_PVTIME_STRUCT_SIZE; > + struct kvm_config *kvm_cfg = NULL; > + struct kvm_device_attr pvtime_attr = (struct kvm_device_attr) { > + .group = KVM_ARM_VCPU_PVTIME_CTRL, > + .addr = KVM_ARM_VCPU_PVTIME_IPA > + }; > + > + kvm_cfg = &vcpu->kvm->cfg; > + if (kvm_cfg->no_pvtime) > + return 0; > + > + if (!pvtime_data.is_failed_cfg) > + return -ENOTSUP; > + > + has_stolen_time = kvm__supports_extension(vcpu->kvm, > + KVM_CAP_STEAL_TIME); > + if (!has_stolen_time) { > + kvm_cfg->no_pvtime = true; > + return 0; > + } > + > + ret = ioctl(vcpu->vcpu_fd, KVM_HAS_DEVICE_ATTR, &pvtime_attr); > + if (ret) { > + perror("KVM_HAS_DEVICE_ATTR failed\n"); > + goto out_err; > + } > + > + if (!pvtime_data.usr_mem) { > + ret = pvtime__alloc_region(vcpu->kvm); > + if (ret) { > + perror("Failed allocating pvtime region\n"); > + goto out_err; > + } > + } > + > + pvtime_attr.addr = (u64)&pvtime_guest_addr; > + ret = ioctl(vcpu->vcpu_fd, KVM_SET_DEVICE_ATTR, &pvtime_attr); > + if (!ret) > + return 0; > + > + perror("KVM_SET_DEVICE_ATTR failed\n"); > + pvtime__teardown_region(vcpu->kvm); > +out_err: > + pvtime_data.is_failed_cfg = false; kvm_cpu__init() calls kvm_cpu__arch_init()->kvm_cpu__setup_pvtime() for each VCPU from the main thread (so sequentually), not from the VCPU threads. If this function returns an error, kvm_cpu__arch_init() calls die(), which means that kvmtool will terminate without calling kvm_cpu__setup_pvtime() for the other VCPUs. What I'm trying to say is that the field is_failed_cfg is not useful, because if one VCPU fails initialization, then kvmtool will not attempt to initialize the rest of the VCPUs. If you drop is_failed_cfg you can also drop the pvtime_data_priv struct and use a static user_mem variable (up to you). > + return ret; > +} > + > +int kvm_cpu__teardown_pvtime(struct kvm *kvm) > +{ > + return pvtime__teardown_region(kvm); > +} > diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h > index c645ac0..43b1f77 100644 > --- a/arm/include/arm-common/kvm-arch.h > +++ b/arm/include/arm-common/kvm-arch.h > @@ -15,7 +15,8 @@ > * | PCI |////| plat | | | | | > * | I/O |////| MMIO: | Flash | virtio | GIC | PCI | DRAM > * | space |////| UART, | | MMIO | | (AXI) | > - * | |////| RTC | | | | | > + * | |////| RTC, | | | | | > + * | |////| PVTIME| | | | | > * +-------+----+-------+-------+--------+-----+---------+---...... > */ > > @@ -34,6 +35,9 @@ > #define ARM_RTC_MMIO_BASE (ARM_UART_MMIO_BASE + ARM_UART_MMIO_SIZE) > #define ARM_RTC_MMIO_SIZE 0x10000 > > +#define ARM_PVTIME_BASE (ARM_RTC_MMIO_BASE + ARM_RTC_MMIO_SIZE) > +#define ARM_PVTIME_SIZE SZ_64K > + > #define KVM_FLASH_MMIO_BASE (ARM_MMIO_AREA + 0x1000000) > #define KVM_FLASH_MAX_SIZE 0x1000000 > > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index 84ac1e9..00660d6 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -144,6 +144,7 @@ void kvm_cpu__arch_nmi(struct kvm_cpu *cpu) > > void kvm_cpu__delete(struct kvm_cpu *vcpu) > { > + kvm_cpu__teardown_pvtime(vcpu->kvm); This causes compilation for aarch32 to fail: arm/kvm-cpu.c: In function ‘kvm_cpu__delete’: arm/kvm-cpu.c:147:2: error: implicit declaration of function ‘kvm_cpu__teardown_pvtime’ [-Werror=implicit-function-declaration] 147 | kvm_cpu__teardown_pvtime(vcpu->kvm); | ^~~~~~~~~~~~~~~~~~~~~~~~ arm/kvm-cpu.c:147:2: error: nested extern declaration of ‘kvm_cpu__teardown_pvtime’ [-Werror=nested-externs] cc1: all warnings being treated as errors make: *** [Makefile:482: arm/kvm-cpu.o] Error 1 The reason for that is that there is no stub for kvm_cpu__teardown_pvtime() for aarch32. This fixes the compilation error for me: diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h index 780e0e2f0934..ae77a136d0ce 100644 --- a/arm/aarch32/include/kvm/kvm-cpu-arch.h +++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h @@ -19,5 +19,9 @@ static inline int kvm_cpu__configure_features(struct kvm_cpu *vcpu) { return 0; } +static inline int kvm_cpu__teardown_pvtime(struct kvm *kvm) +{ + return 0; +} #endif /* KVM__KVM_CPU_ARCH_H */ Thanks, Alex > free(vcpu); > } > > diff --git a/include/kvm/kvm-config.h b/include/kvm/kvm-config.h > index 6a5720c..48adf27 100644 > --- a/include/kvm/kvm-config.h > +++ b/include/kvm/kvm-config.h > @@ -62,6 +62,7 @@ struct kvm_config { > bool no_dhcp; > bool ioport_debug; > bool mmio_debug; > + bool no_pvtime; > }; > > #endif > -- > 2.35.1.616.g0bdcbb4464-goog >