korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-24 12:44:11 +08:00
Code Issues Packages Projects Releases Wiki Activity

KVM: x86: Move Hyper-V partition assist page out of Hyper-V emulation context

Browse Source 
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>
This commit is contained in:
Vitaly Kuznetsov 2023-12-05 11:36:16 +01:00 committed by Sean Christopherson
parent 87562052c9
commit cfef5af3cb
5 changed files with 30 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/kvm_host.h
View File

@ -1125,7 +1125,6 @@ struct kvm_hv {
*/
unsigned int synic_auto_eoi_used;
struct hv_partition_assist_pg *hv_pa_pg;
struct kvm_hv_syndbg hv_syndbg;
};
@ -1447,6 +1446,7 @@ struct kvm_arch {
#if IS_ENABLED(CONFIG_HYPERV)
hpa_t hv_root_tdp;
spinlock_t hv_root_tdp_lock;
struct hv_partition_assist_pg *hv_pa_pg;
#endif
/*
* VM-scope maximum vCPU ID. Used to determine the size of structures

20
arch/x86/kvm/kvm_onhyperv.h
View File

@ -10,6 +10,26 @@
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)
{

10
arch/x86/kvm/svm/svm_onhyperv.c
View File

@ -18,18 +18,14 @@
int svm_hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu)
{
struct hv_vmcb_enlightenments *hve;
struct hv_partition_assist_pg **p_hv_pa_pg =
&to_kvm_hv(vcpu->kvm)->hv_pa_pg;
hpa_t partition_assist_page = hv_get_partition_assist_page(vcpu);
if (!*p_hv_pa_pg)
*p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!*p_hv_pa_pg)
if (partition_assist_page == INVALID_PAGE)
return -ENOMEM;
hve = &to_svm(vcpu)->vmcb->control.hv_enlightenments;
hve->partition_assist_page = __pa(*p_hv_pa_pg);
hve->partition_assist_page = partition_assist_page;
hve->hv_vm_id = (unsigned long)vcpu->kvm;
if (!hve->hv_enlightenments_control.nested_flush_hypercall) {
hve->hv_enlightenments_control.nested_flush_hypercall = 1;

14
arch/x86/kvm/vmx/vmx.c
View File

@ -523,22 +523,14 @@ module_param(enlightened_vmcs, bool, 0444);
static int hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu)
{
struct hv_enlightened_vmcs *evmcs;
struct hv_partition_assist_pg **p_hv_pa_pg =
&to_kvm_hv(vcpu->kvm)->hv_pa_pg;
/*
* Synthetic VM-Exit is not enabled in current code and so All
* evmcs in singe VM shares same assist page.
*/
if (!*p_hv_pa_pg)
*p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
hpa_t partition_assist_page = hv_get_partition_assist_page(vcpu);
if (!*p_hv_pa_pg)
if (partition_assist_page == INVALID_PAGE)
return -ENOMEM;
evmcs = (struct hv_enlightened_vmcs *)to_vmx(vcpu)->loaded_vmcs->vmcs;
evmcs->partition_assist_page =
__pa(*p_hv_pa_pg);
evmcs->partition_assist_page = partition_assist_page;
evmcs->hv_vm_id = (unsigned long)vcpu->kvm;
evmcs->hv_enlightenments_control.nested_flush_hypercall = 1;

4
arch/x86/kvm/x86.c
View File

@ -12438,7 +12438,9 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
void kvm_arch_free_vm(struct kvm *kvm)
{
kfree(to_kvm_hv(kvm)->hv_pa_pg);
#if IS_ENABLED(CONFIG_HYPERV)
kfree(kvm->arch.hv_pa_pg);
#endif
__kvm_arch_free_vm(kvm);
}