linux/arch/x86/kvm/kvm_onhyperv.h
Vitaly Kuznetsov cfef5af3cb KVM: x86: Move Hyper-V partition assist page out of Hyper-V emulation context
Hyper-V partition assist page is used when KVM runs on top of Hyper-V and
is not used for Windows/Hyper-V guests on KVM, this means that 'hv_pa_pg'
placement in 'struct kvm_hv' is unfortunate. As a preparation to making
Hyper-V emulation optional, move 'hv_pa_pg' to 'struct kvm_arch' and put it
under CONFIG_HYPERV.

While on it, introduce hv_get_partition_assist_page() helper to allocate
partition assist page. Move the comment explaining why we use a single page
for all vCPUs from VMX and expand it a bit.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-3-vkuznets@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-12-07 09:34:01 -08:00

45 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* KVM L1 hypervisor optimizations on Hyper-V.
*/
#ifndef __ARCH_X86_KVM_KVM_ONHYPERV_H__
#define __ARCH_X86_KVM_KVM_ONHYPERV_H__
#if IS_ENABLED(CONFIG_HYPERV)
int hv_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, gfn_t nr_pages);
int hv_flush_remote_tlbs(struct kvm *kvm);
void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp);
static inline hpa_t hv_get_partition_assist_page(struct kvm_vcpu *vcpu)
{
/*
* Partition assist page is something which Hyper-V running in L0
* requires from KVM running in L1 before direct TLB flush for L2
* guests can be enabled. KVM doesn't currently use the page but to
* comply with TLFS it still needs to be allocated. For now, this
* is a single page shared among all vCPUs.
*/
struct hv_partition_assist_pg **p_hv_pa_pg =
&vcpu->kvm->arch.hv_pa_pg;
if (!*p_hv_pa_pg)
*p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
if (!*p_hv_pa_pg)
return INVALID_PAGE;
return __pa(*p_hv_pa_pg);
}
#else /* !CONFIG_HYPERV */
static inline int hv_flush_remote_tlbs(struct kvm *kvm)
{
return -EOPNOTSUPP;
}
static inline void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
{
}
#endif /* !CONFIG_HYPERV */
#endif