Re: [PATCH v2 2/3] KVM: VMX: Rename {vmx,nested_vmx}_vcpu_setup() and minor cleanup

From: Xiaoyao Li
Date: Fri Oct 18 2019 - 14:38:36 EST


On 10/19/2019 1:09 AM, Sean Christopherson wrote:
On Fri, Oct 18, 2019 at 05:37:22PM +0800, Xiaoyao Li wrote:
Rename {vmx,nested_vmx}_vcpu_setup() to {vmx,nested_vmx}_vmcs_setup,
to match what they really do.

Aslo remove the vmcs unrelated codes to vmx_vcpu_create().

Do this in a separate patch, just in case there is a dependencies we're
missing.

The initialization of vmx->hv_deadline_tsc can be removed here, because
it will be called in vmx_vcpu_reset() as the flow:

kvm_arch_vcpu_setup()
-> kvm_vcpu_reset()
-> vmx_vcpu_reset()

Definitely needs to be in a separate patch.


OK, I'll split it into 3 patches.


Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
Changes in v2:
- move out the vmcs unrelated codes
---
arch/x86/kvm/vmx/nested.c | 2 +-
arch/x86/kvm/vmx/nested.h | 2 +-
arch/x86/kvm/vmx/vmx.c | 45 +++++++++++++++++----------------------
3 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 5e231da00310..7935422d311f 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5768,7 +5768,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
return ret;
}
-void nested_vmx_vcpu_setup(void)
+void nested_vmx_vmcs_setup(void)

"vmcs_setup" sounds like we're allocating and loading a VMCS. Maybe
{nested_,}vmx_set_initial_vmcs_state() a la vmx_set_constant_host_state()?

{
if (enable_shadow_vmcs) {
vmcs_write64(VMREAD_BITMAP, __pa(vmx_vmread_bitmap));
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
index 187d39bf0bf1..2be1ba7482c9 100644
--- a/arch/x86/kvm/vmx/nested.h
+++ b/arch/x86/kvm/vmx/nested.h
@@ -11,7 +11,7 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps,
bool apicv);
void nested_vmx_hardware_unsetup(void);
__init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *));
-void nested_vmx_vcpu_setup(void);
+void nested_vmx_vmcs_setup(void);
void nested_vmx_free_vcpu(struct kvm_vcpu *vcpu);
int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, bool from_vmentry);
bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ef567df344bf..b083316a598d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4161,15 +4161,10 @@ static void ept_set_mmio_spte_mask(void)
#define VMX_XSS_EXIT_BITMAP 0
-/*
- * Sets up the vmcs for emulated real mode.
- */
-static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
+static void vmx_vmcs_setup(struct vcpu_vmx *vmx)
{
- int i;
-
if (nested)
- nested_vmx_vcpu_setup();
+ nested_vmx_vmcs_setup();
if (cpu_has_vmx_msr_bitmap())
vmcs_write64(MSR_BITMAP, __pa(vmx->vmcs01.msr_bitmap));
@@ -4178,7 +4173,6 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
/* Control */
pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx));
- vmx->hv_deadline_tsc = -1;
exec_controls_set(vmx, vmx_exec_control(vmx));
@@ -4227,21 +4221,6 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);
- for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
- u32 index = vmx_msr_index[i];
- u32 data_low, data_high;
- int j = vmx->nmsrs;
-
- if (rdmsr_safe(index, &data_low, &data_high) < 0)
- continue;
- if (wrmsr_safe(index, data_low, data_high) < 0)
- continue;
- vmx->guest_msrs[j].index = i;
- vmx->guest_msrs[j].data = 0;
- vmx->guest_msrs[j].mask = -1ull;
- ++vmx->nmsrs;
- }
-
vm_exit_controls_set(vmx, vmx_vmexit_ctrl());
/* 22.2.1, 20.8.1 */
@@ -6710,7 +6689,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
int err;
struct vcpu_vmx *vmx;
unsigned long *msr_bitmap;
- int cpu;
+ int i, cpu;
BUILD_BUG_ON_MSG(offsetof(struct vcpu_vmx, vcpu) != 0,
"struct kvm_vcpu must be at offset 0 for arch usercopy region");
@@ -6786,9 +6765,25 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
cpu = get_cpu();
vmx_vcpu_load(&vmx->vcpu, cpu);
vmx->vcpu.cpu = cpu;
- vmx_vcpu_setup(vmx);
+ vmx_vmcs_setup(vmx);
vmx_vcpu_put(&vmx->vcpu);
put_cpu();
+
+ for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
+ u32 index = vmx_msr_index[i];
+ u32 data_low, data_high;
+ int j = vmx->nmsrs;
+
+ if (rdmsr_safe(index, &data_low, &data_high) < 0)
+ continue;
+ if (wrmsr_safe(index, data_low, data_high) < 0)
+ continue;
+ vmx->guest_msrs[j].index = i;
+ vmx->guest_msrs[j].data = 0;
+ vmx->guest_msrs[j].mask = -1ull;
+ ++vmx->nmsrs;
+ }

I'd put this immediately after guest_msrs is allocated. Yeah, we'll waste
a few cycles if allocating vmcs01 fails, but that should be a very rare
event.


OK.

+
if (cpu_need_virtualize_apic_accesses(&vmx->vcpu)) {
err = alloc_apic_access_page(kvm);
if (err)
--
2.19.1