lkml.org 
[lkml]   [2018]   [Apr]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/5] KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation
Date
Implement HvFlushVirtualAddress{List,Space} hypercalls in a simplistic way:
do full TLB flush with KVM_REQ_TLB_FLUSH and rely on kvm_vcpu_kick()
kicking only vCPUs which are currently IN_GUEST_MODE.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/hyperv.c | 54 ++++++++++++++++++++++++++++++++++++++++++++-------
arch/x86/kvm/trace.h | 24 +++++++++++++++++++++++
2 files changed, 71 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 3cb3bb68db7e..aa866994366d 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1242,6 +1242,49 @@ int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
return kvm_hv_get_msr(vcpu, msr, pdata);
}

+static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
+ u16 rep_cnt)
+{
+ struct kvm *kvm = current_vcpu->kvm;
+ struct hv_tlb_flush flush;
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ if (unlikely(kvm_read_guest(kvm, ingpa, &flush, sizeof(flush))))
+ return HV_STATUS_INVALID_HYPERCALL_INPUT;
+
+ trace_kvm_hv_flush_tlb(flush.processor_mask, flush.address_space,
+ flush.flags);
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
+
+ if (!(flush.flags & HV_FLUSH_ALL_PROCESSORS) &&
+ !(flush.processor_mask & BIT_ULL(hv->vp_index)))
+ continue;
+
+ /*
+ * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we
+ * can't analyze it here, flush TLB regardless of the specified
+ * address space.
+ */
+ kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
+
+ /*
+ * It is very unlikely but possible that we're doing an extra
+ * kick here (e.g. if the vCPU has just entered the guest and
+ * has its TLB flushed).
+ */
+ if (vcpu != current_vcpu)
+ kvm_vcpu_kick(vcpu);
+ }
+
+ /* We always do full TLB flush, set rep_done = rep_cnt. */
+ return (u64)HV_STATUS_SUCCESS |
+ ((u64)rep_cnt << HV_HYPERCALL_REP_START_OFFSET) |
+ ((u64)rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
+}
+
bool kvm_hv_hypercall_enabled(struct kvm *kvm)
{
return READ_ONCE(kvm->arch.hyperv.hv_hypercall) & HV_X64_MSR_HYPERCALL_ENABLE;
@@ -1345,12 +1388,6 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)

trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);

- /* Hypercall continuation is not supported yet */
- if (rep_cnt || rep_idx) {
- ret = HV_STATUS_INVALID_HYPERCALL_CODE;
- goto set_result;
- }
-
switch (code) {
case HVCALL_NOTIFY_LONG_SPIN_WAIT:
kvm_vcpu_on_spin(vcpu, true);
@@ -1374,12 +1411,15 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
vcpu->arch.complete_userspace_io =
kvm_hv_hypercall_complete_userspace;
return 0;
+ case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
+ case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
+ ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt);
+ break;
default:
ret = HV_STATUS_INVALID_HYPERCALL_CODE;
break;
}

-set_result:
kvm_hv_hypercall_set_result(vcpu, ret);
return 1;
}
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 9807c314c478..47a4fd758743 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1367,6 +1367,30 @@ TRACE_EVENT(kvm_hv_timer_state,
__entry->vcpu_id,
__entry->hv_timer_in_use)
);
+
+/*
+ * Tracepoint for kvm_hv_flush_tlb.
+ */
+TRACE_EVENT(kvm_hv_flush_tlb,
+ TP_PROTO(u64 processor_mask, u64 address_space, u64 flags),
+ TP_ARGS(processor_mask, address_space, flags),
+
+ TP_STRUCT__entry(
+ __field(u64, processor_mask)
+ __field(u64, address_space)
+ __field(u64, flags)
+ ),
+
+ TP_fast_assign(
+ __entry->processor_mask = processor_mask;
+ __entry->address_space = address_space;
+ __entry->flags = flags;
+ ),
+
+ TP_printk("processor_mask 0x%llx address_space 0x%llx flags 0x%llx",
+ __entry->processor_mask, __entry->address_space,
+ __entry->flags)
+);
#endif /* _TRACE_KVM_H */

#undef TRACE_INCLUDE_PATH
--
2.14.3
\
 
 \ /
  Last update: 2018-04-02 18:12    [W:0.085 / U:5.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site