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  1. 25 6月, 2012 3 次提交
    • M
      KVM guest: guest side for eoi avoidance · ab9cf499
      由 Michael S. Tsirkin 提交于 
      The idea is simple: there's a bit, per APIC, in guest memory,
that tells the guest that it does not need EOI.
Guest tests it using a single est and clear operation - this is
necessary so that host can detect interrupt nesting - and if set, it can
skip the EOI MSR.

I run a simple microbenchmark to show exit reduction
(note: for testing, need to apply follow-up patch
'kvm: host side for eoi optimization' + a qemu patch
 I posted separately, on host):

Before:

Performance counter stats for 'sleep 1s':

            47,357 kvm:kvm_entry                                                [99.98%]
                 0 kvm:kvm_hypercall                                            [99.98%]
                 0 kvm:kvm_hv_hypercall                                         [99.98%]
             5,001 kvm:kvm_pio                                                  [99.98%]
                 0 kvm:kvm_cpuid                                                [99.98%]
            22,124 kvm:kvm_apic                                                 [99.98%]
            49,849 kvm:kvm_exit                                                 [99.98%]
            21,115 kvm:kvm_inj_virq                                             [99.98%]
                 0 kvm:kvm_inj_exception                                        [99.98%]
                 0 kvm:kvm_page_fault                                           [99.98%]
            22,937 kvm:kvm_msr                                                  [99.98%]
                 0 kvm:kvm_cr                                                   [99.98%]
                 0 kvm:kvm_pic_set_irq                                          [99.98%]
                 0 kvm:kvm_apic_ipi                                             [99.98%]
            22,207 kvm:kvm_apic_accept_irq                                      [99.98%]
            22,421 kvm:kvm_eoi                                                  [99.98%]
                 0 kvm:kvm_pv_eoi                                               [99.99%]
                 0 kvm:kvm_nested_vmrun                                         [99.99%]
                 0 kvm:kvm_nested_intercepts                                    [99.99%]
                 0 kvm:kvm_nested_vmexit                                        [99.99%]
                 0 kvm:kvm_nested_vmexit_inject                                    [99.99%]
                 0 kvm:kvm_nested_intr_vmexit                                    [99.99%]
                 0 kvm:kvm_invlpga                                              [99.99%]
                 0 kvm:kvm_skinit                                               [99.99%]
                57 kvm:kvm_emulate_insn                                         [99.99%]
                 0 kvm:vcpu_match_mmio                                          [99.99%]
                 0 kvm:kvm_userspace_exit                                       [99.99%]
                 2 kvm:kvm_set_irq                                              [99.99%]
                 2 kvm:kvm_ioapic_set_irq                                       [99.99%]
            23,609 kvm:kvm_msi_set_irq                                          [99.99%]
                 1 kvm:kvm_ack_irq                                              [99.99%]
               131 kvm:kvm_mmio                                                 [99.99%]
               226 kvm:kvm_fpu                                                  [100.00%]
                 0 kvm:kvm_age_page                                             [100.00%]
                 0 kvm:kvm_try_async_get_page                                    [100.00%]
                 0 kvm:kvm_async_pf_doublefault                                    [100.00%]
                 0 kvm:kvm_async_pf_not_present                                    [100.00%]
                 0 kvm:kvm_async_pf_ready                                       [100.00%]
                 0 kvm:kvm_async_pf_completed

       1.002100578 seconds time elapsed

After:

 Performance counter stats for 'sleep 1s':

            28,354 kvm:kvm_entry                                                [99.98%]
                 0 kvm:kvm_hypercall                                            [99.98%]
                 0 kvm:kvm_hv_hypercall                                         [99.98%]
             1,347 kvm:kvm_pio                                                  [99.98%]
                 0 kvm:kvm_cpuid                                                [99.98%]
             1,931 kvm:kvm_apic                                                 [99.98%]
            29,595 kvm:kvm_exit                                                 [99.98%]
            24,884 kvm:kvm_inj_virq                                             [99.98%]
                 0 kvm:kvm_inj_exception                                        [99.98%]
                 0 kvm:kvm_page_fault                                           [99.98%]
             1,986 kvm:kvm_msr                                                  [99.98%]
                 0 kvm:kvm_cr                                                   [99.98%]
                 0 kvm:kvm_pic_set_irq                                          [99.98%]
                 0 kvm:kvm_apic_ipi                                             [99.99%]
            25,953 kvm:kvm_apic_accept_irq                                      [99.99%]
            26,132 kvm:kvm_eoi                                                  [99.99%]
            26,593 kvm:kvm_pv_eoi                                               [99.99%]
                 0 kvm:kvm_nested_vmrun                                         [99.99%]
                 0 kvm:kvm_nested_intercepts                                    [99.99%]
                 0 kvm:kvm_nested_vmexit                                        [99.99%]
                 0 kvm:kvm_nested_vmexit_inject                                    [99.99%]
                 0 kvm:kvm_nested_intr_vmexit                                    [99.99%]
                 0 kvm:kvm_invlpga                                              [99.99%]
                 0 kvm:kvm_skinit                                               [99.99%]
               284 kvm:kvm_emulate_insn                                         [99.99%]
                68 kvm:vcpu_match_mmio                                          [99.99%]
                68 kvm:kvm_userspace_exit                                       [99.99%]
                 2 kvm:kvm_set_irq                                              [99.99%]
                 2 kvm:kvm_ioapic_set_irq                                       [99.99%]
            28,288 kvm:kvm_msi_set_irq                                          [99.99%]
                 1 kvm:kvm_ack_irq                                              [99.99%]
               131 kvm:kvm_mmio                                                 [100.00%]
               588 kvm:kvm_fpu                                                  [100.00%]
                 0 kvm:kvm_age_page                                             [100.00%]
                 0 kvm:kvm_try_async_get_page                                    [100.00%]
                 0 kvm:kvm_async_pf_doublefault                                    [100.00%]
                 0 kvm:kvm_async_pf_not_present                                    [100.00%]
                 0 kvm:kvm_async_pf_ready                                       [100.00%]
                 0 kvm:kvm_async_pf_completed

       1.002039622 seconds time elapsed

We see that # of exits is almost halved.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      ab9cf499
    • M
      KVM: optimize ISR lookups · 8680b94b
      由 Michael S. Tsirkin 提交于 
      We perform ISR lookups twice: during interrupt
injection and on EOI. Typical workloads only have
a single bit set there. So we can avoid ISR scans by
1. counting bits as we set/clear them in ISR
2. on set, caching the injected vector number
3. on clear, invalidating the cache

The real purpose of this is enabling PV EOI
which needs to quickly validate the vector.
But non PV guests also benefit: with this patch,
and without interrupt nesting, apic_find_highest_isr
will always return immediately without scanning ISR.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      8680b94b
    • M
      KVM: document lapic regs field · 5eadf916
      由 Michael S. Tsirkin 提交于 
      Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      5eadf916
  3. 19 6月, 2012 1 次提交
  5. 18 6月, 2012 2 次提交
  7. 14 6月, 2012 4 次提交
  9. 12 6月, 2012 1 次提交
  11. 06 6月, 2012 4 次提交
    • A
      Merge branch 'for-upstream' of git://github.com/agraf/linux-2.6 into next · 25e531a9
      由 Avi Kivity 提交于 
      Alex says:

"Changes this time include:

  - Generalize KVM_GUEST support to overall ePAPR code
  - Fix reset for Book3S HV
  - Fix machine check deferral when CONFIG_KVM_GUEST=y
  - Add support for BookE register DECAR"

* 'for-upstream' of git://github.com/agraf/linux-2.6:
  KVM: PPC: Not optimizing MSR_CE and MSR_ME with paravirt.
  KVM: PPC: booke: Added DECAR support
  KVM: PPC: Book3S HV: Make the guest hash table size configurable
  KVM: PPC: Factor out guest epapr initialization
Signed-off-by: NAvi Kivity <avi@redhat.com>
      25e531a9
    • M
      KVM: disable uninitialized var warning · 79f702a6
      由 Michael S. Tsirkin 提交于 
      I see this in 3.5-rc1:

arch/x86/kvm/mmu.c: In function ‘kvm_test_age_rmapp’:
arch/x86/kvm/mmu.c:1271: warning: ‘iter.desc’ may be used uninitialized in this function

The line in question was introduced by commit
1e3f42f0

 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
                              unsigned long data)
 {
-       u64 *spte;
+       u64 *sptep;
+       struct rmap_iterator iter;   <- line 1271
        int young = 0;

        /*

The reason I think is that the compiler assumes that
the rmap value could be 0, so

static u64 *rmap_get_first(unsigned long rmap, struct rmap_iterator
*iter)
{
        if (!rmap)
                return NULL;

        if (!(rmap & 1)) {
                iter->desc = NULL;
                return (u64 *)rmap;
        }

        iter->desc = (struct pte_list_desc *)(rmap & ~1ul);
        iter->pos = 0;
        return iter->desc->sptes[iter->pos];
}

will not initialize iter.desc, but the compiler isn't
smart enough to see that

        for (sptep = rmap_get_first(*rmapp, &iter); sptep;
             sptep = rmap_get_next(&iter)) {

will immediately exit in this case.
I checked by adding
        if (!*rmapp)
                goto out;
on top which is clearly equivalent but disables the warning.

This patch uses uninitialized_var to disable the warning without
increasing code size.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      79f702a6
    • C
      KVM: Cleanup the kvm_print functions and introduce pr_XX wrappers · a737f256
      由 Christoffer Dall 提交于 
      Introduces a couple of print functions, which are essentially wrappers
around standard printk functions, with a KVM: prefix.

Functions introduced or modified are:
 - kvm_err(fmt, ...)
 - kvm_info(fmt, ...)
 - kvm_debug(fmt, ...)
 - kvm_pr_unimpl(fmt, ...)
 - pr_unimpl(vcpu, fmt, ...) -> vcpu_unimpl(vcpu, fmt, ...)
Signed-off-by: NChristoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      a737f256
    • C
      KVM: s390: Change maintainer · 4ae57b6c
      由 Christian Borntraeger 提交于 
      Since Carsten is now working on a different project, Cornelia will
work as the 2nd s390/kvm maintainer.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
CC: Carsten Otte <cotte@de.ibm.com>
CC: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      4ae57b6c
  13. 05 6月, 2012 17 次提交
  15. 04 6月, 2012 5 次提交
  17. 03 6月, 2012 3 次提交