Glauber de Oliveira Costa wrote:
> This is the host part of kvm clocksource implementation. As it does
> not include clockevents, it is a fairly simple implementation. We
> only have to register a per-vcpu area, and start writting to it periodically.
>
> The area is binary compatible with xen, as we use the same shadow_info
> structure.
>
> Signed-off-by: Glauber de Oliveira Costa <[EMAIL PROTECTED]>
> ---
> arch/x86/kvm/x86.c | 98
> +++++++++++++++++++++++++++++++++++++++++++-
> include/asm-x86/kvm_host.h | 6 +++
> include/asm-x86/kvm_para.h | 24 +++++++++++
> include/linux/kvm.h | 1 +
> 4 files changed, 128 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 8a90403..fd69aa1 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -19,6 +19,7 @@
> #include "irq.h"
> #include "mmu.h"
>
> +#include <linux/clocksource.h>
> #include <linux/kvm.h>
> #include <linux/fs.h>
> #include <linux/vmalloc.h>
> @@ -412,7 +413,7 @@ static u32 msrs_to_save[] = {
> #ifdef CONFIG_X86_64
> MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
> #endif
> - MSR_IA32_TIME_STAMP_COUNTER,
> + MSR_IA32_TIME_STAMP_COUNTER, MSR_KVM_SYSTEM_TIME,
>
Missing second MSR here.
>
> +static void kvm_write_wall_clock(struct kvm_vcpu *v, gpa_t wall_clock)
> +{
> + int version = 1;
> + struct wall_clock wc;
> + unsigned long flags;
> + struct timespec wc_ts;
> +
> + local_irq_save(flags);
> + kvm_get_msr(v, MSR_IA32_TIME_STAMP_COUNTER,
> + &v->arch.hv_clock.tsc_timestamp);
> + wc_ts = current_kernel_time();
> + local_irq_restore(flags);
> +
> + down_write(¤t->mm->mmap_sem);
> + kvm_write_guest(v->kvm, wall_clock, &version, sizeof(version));
> + up_write(¤t->mm->mmap_sem);
> +
> + /* With all the info we got, fill in the values */
> + wc.wc_sec = wc_ts.tv_sec;
> + wc.wc_nsec = wc_ts.tv_nsec;
> + wc.wc_version = ++version;
> +
> + down_write(¤t->mm->mmap_sem);
> + kvm_write_guest(v->kvm, wall_clock, &wc, sizeof(wc));
> + up_write(¤t->mm->mmap_sem);
> +}
>
missing blank line
> +static void kvm_write_guest_time(struct kvm_vcpu *v)
> +{
> + struct timespec ts;
> + unsigned long flags;
> + struct kvm_vcpu_arch *vcpu = &v->arch;
> + void *shared_kaddr;
> +
> + if ((!vcpu->time_page))
> + return;
> +
> + /* Keep irq disabled to prevent changes to the clock */
> + local_irq_save(flags);
> + kvm_get_msr(v, MSR_IA32_TIME_STAMP_COUNTER,
> + &vcpu->hv_clock.tsc_timestamp);
> + ktime_get_ts(&ts);
> + local_irq_restore(flags);
> +
> + /* With all the info we got, fill in the values */
> +
> + vcpu->hv_clock.system_time = ts.tv_nsec +
> + (NSEC_PER_SEC * (u64)ts.tv_sec);
> + /*
> + * The interface expects us to write an even number signaling that the
> + * update is finished. Since the guest won't see the intermediate
> states,
> + * we just write "2" at the end
> + */
> + vcpu->hv_clock.version = 2;
> +
> + preempt_disable();
>
vcpu_load() is not preemptible anyway (and cannot be).
> +
> + shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0);
> +
> + memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock,
> + sizeof(vcpu->hv_clock));
> +
> + kunmap_atomic(shared_kaddr, KM_USER0);
> + preempt_enable();
> +
> + mark_page_dirty(v->kvm, vcpu->time >> PAGE_SHIFT);
> +}
> +
>
> int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
> {
> @@ -494,6 +562,25 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr,
> u64 data)
> case MSR_IA32_MISC_ENABLE:
> vcpu->arch.ia32_misc_enable_msr = data;
> break;
> + case MSR_KVM_WALL_CLOCK:
> + vcpu->arch.wall_clock = data;
>
This better be a global msr (in kvm->, not vcpu->). There is precedent;
some msrs in hyperthreading-capable processors are global to a core.
We need some notification to update wall clock as a result of
time-of-day step changes, due to ntp or the user setting the date.
Hopefully such a notifier exists.
--
error compiling committee.c: too many arguments to function
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