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KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently

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Currently, HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls are handled
the exact same way as HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE{,EX}: by
flushing the whole VPID and this is sub-optimal. Switch to handling
these requests with 'flush_tlb_gva()' hooks instead. Use the newly
introduced TLB flush fifo to queue the requests.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-12-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Vitaly Kuznetsov 2022-11-01 15:53:49 +01:00 committed by Paolo Bonzini
parent 56b5354fd8
commit 260970862c
1 changed files with 96 additions and 17 deletions
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113
arch/x86/kvm/hyperv.c
View File

@ -1800,7 +1800,14 @@ static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,
sparse_banks, consumed_xmm_halves, offset);
}
static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu)
static int kvm_hv_get_tlb_flush_entries(struct kvm *kvm, struct kvm_hv_hcall *hc, u64 entries[],
int consumed_xmm_halves, gpa_t offset)
{
return kvm_hv_get_hc_data(kvm, hc, hc->rep_cnt, hc->rep_cnt,
entries, consumed_xmm_halves, offset);
}
static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu, u64 *entries, int count)
{
struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
@ -1811,24 +1818,64 @@ static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu)
tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo;
kfifo_in_spinlocked_noirqsave(&tlb_flush_fifo->entries, &flush_all_entry,
1, &tlb_flush_fifo->write_lock);
spin_lock(&tlb_flush_fifo->write_lock);
/*
* All entries should fit on the fifo leaving one free for 'flush all'
* entry in case another request comes in. In case there's not enough
* space, just put 'flush all' entry there.
*/
if (count && entries && count < kfifo_avail(&tlb_flush_fifo->entries)) {
WARN_ON(kfifo_in(&tlb_flush_fifo->entries, entries, count) != count);
goto out_unlock;
}
/*
* Note: full fifo always contains 'flush all' entry, no need to check the
* return value.
*/
kfifo_in(&tlb_flush_fifo->entries, &flush_all_entry, 1);
out_unlock:
spin_unlock(&tlb_flush_fifo->write_lock);
}
int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
u64 entries[KVM_HV_TLB_FLUSH_FIFO_SIZE];
int i, j, count;
gva_t gva;
if (!hv_vcpu)
if (!tdp_enabled || !hv_vcpu)
return -EINVAL;
tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo;
count = kfifo_out(&tlb_flush_fifo->entries, entries, KVM_HV_TLB_FLUSH_FIFO_SIZE);
for (i = 0; i < count; i++) {
if (entries[i] == KVM_HV_TLB_FLUSHALL_ENTRY)
goto out_flush_all;
/*
* Lower 12 bits of 'address' encode the number of additional
* pages to flush.
*/
gva = entries[i] & PAGE_MASK;
for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++)
static_call(kvm_x86_flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE);
++vcpu->stat.tlb_flush;
}
return 0;
out_flush_all:
kfifo_reset_out(&tlb_flush_fifo->entries);
/* Precise flushing isn't implemented yet. */
return -EOPNOTSUPP;
/* Fall back to full flush. */
return -ENOSPC;
}
static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
@ -1837,11 +1884,21 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
struct hv_tlb_flush_ex flush_ex;
struct hv_tlb_flush flush;
DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
/*
* Normally, there can be no more than 'KVM_HV_TLB_FLUSH_FIFO_SIZE'
* entries on the TLB flush fifo. The last entry, however, needs to be
* always left free for 'flush all' entry which gets placed when
* there is not enough space to put all the requested entries.
*/
u64 __tlb_flush_entries[KVM_HV_TLB_FLUSH_FIFO_SIZE - 1];
u64 *tlb_flush_entries;
u64 valid_bank_mask;
u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
struct kvm_vcpu *v;
unsigned long i;
bool all_cpus;
int consumed_xmm_halves = 0;
gpa_t data_offset;
/*
* The Hyper-V TLFS doesn't allow more than 64 sparse banks, e.g. the
@ -1857,10 +1914,12 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
flush.address_space = hc->ingpa;
flush.flags = hc->outgpa;
flush.processor_mask = sse128_lo(hc->xmm[0]);
consumed_xmm_halves = 1;
} else {
if (unlikely(kvm_read_guest(kvm, hc->ingpa,
&flush, sizeof(flush))))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
data_offset = sizeof(flush);
}
trace_kvm_hv_flush_tlb(flush.processor_mask,
@ -1884,10 +1943,12 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
flush_ex.flags = hc->outgpa;
memcpy(&flush_ex.hv_vp_set,
&hc->xmm[0], sizeof(hc->xmm[0]));
consumed_xmm_halves = 2;
} else {
if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
sizeof(flush_ex))))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
data_offset = sizeof(flush_ex);
}
trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
@ -1902,26 +1963,44 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
if (hc->var_cnt != hweight64(valid_bank_mask))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
if (all_cpus)
goto do_flush;
if (!all_cpus) {
if (!hc->var_cnt)
goto ret_success;
if (!hc->var_cnt)
goto ret_success;
if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks,
consumed_xmm_halves, data_offset))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
}
if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, 2,
offsetof(struct hv_tlb_flush_ex,
hv_vp_set.bank_contents)))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
/*
* Hyper-V TLFS doesn't explicitly forbid non-empty sparse vCPU
* banks (and, thus, non-zero 'var_cnt') for the 'all vCPUs'
* case (HV_GENERIC_SET_ALL). Always adjust data_offset and
* consumed_xmm_halves to make sure TLB flush entries are read
* from the correct offset.
*/
data_offset += hc->var_cnt * sizeof(sparse_banks[0]);
consumed_xmm_halves += hc->var_cnt;
}
if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE ||
hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX ||
hc->rep_cnt > ARRAY_SIZE(__tlb_flush_entries)) {
tlb_flush_entries = NULL;
} else {
if (kvm_hv_get_tlb_flush_entries(kvm, hc, __tlb_flush_entries,
consumed_xmm_halves, data_offset))
return HV_STATUS_INVALID_HYPERCALL_INPUT;
tlb_flush_entries = __tlb_flush_entries;
}
do_flush:
/*
* 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.
*/
if (all_cpus) {
kvm_for_each_vcpu(i, v, kvm)
hv_tlb_flush_enqueue(v);
hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt);
kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
} else {
@ -1931,7 +2010,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
v = kvm_get_vcpu(kvm, i);
if (!v)
continue;
hv_tlb_flush_enqueue(v);
hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt);
}
kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);