From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Roman Kagan" <rkagan@virtuozzo.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
"Haiyang Zhang" <haiyangz@microsoft.com>,
"Stephen Hemminger" <sthemmin@microsoft.com>,
"Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>,
linux-kernel@vger.kernel.org, "Jim Mattson" <jmattson@google.com>,
"Liran Alon" <liran.alon@oracle.com>
Subject: [PATCH v6 06/13] KVM: nVMX: optimize prepare_vmcs02{,_full} for Enlightened VMCS case
Date: Tue, 16 Oct 2018 18:50:04 +0200 [thread overview]
Message-ID: <20181016165011.6607-7-vkuznets@redhat.com> (raw)
In-Reply-To: <20181016165011.6607-1-vkuznets@redhat.com>
When Enlightened VMCS is in use by L1 hypervisor we can avoid vmwriting
VMCS fields which did not change.
Our first goal is to achieve minimal impact on traditional VMCS case so
we're not wrapping each vmwrite() with an if-changed checker. We also can't
utilize static keys as Enlightened VMCS usage is per-guest.
This patch implements the simpliest solution: checking fields in groups.
We skip single vmwrite() statements as doing the check will cost us
something even in non-evmcs case and the win is tiny. Unfortunately, this
makes prepare_vmcs02_full{,_full}() code Enlightened VMCS-dependent (and
a bit ugly).
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/vmx.c | 118 +++++++++++++++++++++++++--------------------
1 file changed, 65 insertions(+), 53 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cfb44acd4291..0b665c74fadc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12699,43 +12699,62 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
{
- vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
- vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
- vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);
- vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
- vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector);
- vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);
- vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);
- vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);
- vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);
- vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);
- vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
- vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit);
- vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit);
- vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit);
- vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);
- vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);
- vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);
- vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);
- vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);
- vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);
- vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);
- vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);
- vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);
- vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);
- vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);
- vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
- vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base);
- vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base);
- vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base);
- vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
- vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
-
- vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs);
- vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
- vmcs12->guest_pending_dbg_exceptions);
- vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
- vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);
+ struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;
+
+ if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
+ HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {
+ vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
+ vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
+ vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);
+ vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
+ vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector);
+ vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);
+ vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);
+ vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);
+ vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);
+ vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);
+ vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
+ vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit);
+ vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit);
+ vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit);
+ vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);
+ vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);
+ vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);
+ vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);
+ vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);
+ vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);
+ vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);
+ vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);
+ vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);
+ vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);
+ vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);
+ vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
+ vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base);
+ vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base);
+ vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base);
+ vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
+ vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
+ }
+
+ if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
+ HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1)) {
+ vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs);
+ vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
+ vmcs12->guest_pending_dbg_exceptions);
+ vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
+ vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);
+
+ /*
+ * L1 may access the L2's PDPTR, so save them to construct
+ * vmcs12
+ */
+ if (enable_ept) {
+ vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0);
+ vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1);
+ vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2);
+ vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3);
+ }
+ }
if (nested_cpu_has_xsaves(vmcs12))
vmcs_write64(XSS_EXIT_BITMAP, vmcs12->xss_exit_bitmap);
@@ -12778,16 +12797,6 @@ static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
else
vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
}
-
- /*
- * L1 may access the L2's PDPTR, so save them to construct vmcs12
- */
- if (enable_ept) {
- vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0);
- vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1);
- vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2);
- vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3);
- }
}
/*
@@ -12805,6 +12814,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
u32 *entry_failure_code)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;
if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs) {
prepare_vmcs02_full(vmx, vmcs12);
@@ -12815,12 +12825,14 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
* First, the fields that are shadowed. This must be kept in sync
* with vmx_shadow_fields.h.
*/
-
- vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
- vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);
- vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);
- vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);
- vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);
+ if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
+ HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {
+ vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
+ vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);
+ vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);
+ vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);
+ vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);
+ }
if (vmx->nested.nested_run_pending &&
(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) {
--
2.17.1
next prev parent reply other threads:[~2018-10-16 16:50 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-16 16:49 [PATCH v6 00/13] KVM: nVMX: Enlightened VMCS for Hyper-V on KVM Vitaly Kuznetsov
2018-10-16 16:49 ` [PATCH v6 01/13] KVM: hyperv: define VP assist page helpers Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 02/13] KVM: VMX: refactor evmcs_sanitize_exec_ctrls() Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 03/13] KVM: nVMX: add KVM_CAP_HYPERV_ENLIGHTENED_VMCS capability Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 04/13] KVM: nVMX: add enlightened VMCS state Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 05/13] KVM: nVMX: implement enlightened VMPTRLD and VMCLEAR Vitaly Kuznetsov
2018-12-12 23:19 ` Jim Mattson
2018-12-13 10:26 ` Vitaly Kuznetsov
2018-10-16 16:50 ` Vitaly Kuznetsov [this message]
2018-10-16 21:55 ` [PATCH v6 06/13] KVM: nVMX: optimize prepare_vmcs02{,_full} for Enlightened VMCS case Paolo Bonzini
2018-10-17 14:47 ` Vitaly Kuznetsov
2018-10-17 17:02 ` Paolo Bonzini
2018-10-17 17:08 ` Jim Mattson
2018-10-17 17:17 ` Paolo Bonzini
2018-10-18 11:14 ` Vitaly Kuznetsov
2018-10-18 12:42 ` Paolo Bonzini
2018-10-16 16:50 ` [PATCH v6 07/13] x86/kvm/hyperv: don't clear VP assist pages on init Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 08/13] x86/kvm/lapic: preserve gfn_to_hva_cache len on cache reinit Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 09/13] x86/kvm/nVMX: allow bare VMXON state migration Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 10/13] KVM: selftests: state_test: test bare VMXON migration Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 11/13] x86/kvm/nVMX: nested state migration for Enlightened VMCS Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 12/13] tools/headers: update kvm.h Vitaly Kuznetsov
2018-10-16 16:50 ` [PATCH v6 13/13] KVM: selftests: add Enlightened VMCS test Vitaly Kuznetsov
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