vmm_exclusive=0 leads to KVM setting X86_CR4_VMXE always and calling
VMXON only when the vcpu is loaded. X86_CR4_VMXE is used as an
indication in cpu_emergency_vmxoff() (called on kdump) if VMXOFF has to be
called. This is obviously not the case if both are used independtly.
Calling VMXOFF without a previous VMXON will result in an exception.
In addition, X86_CR4_VMXE is used as a mean to test if VMX is already in
use by another VMM in hardware_enable(). So there can't really be
co-existance. If the other VMM is prepared for co-existance and does a
similar check, only one VMM can exist. If the other VMM is not prepared
and blindly sets/clears X86_CR4_VMXE, we will get inconsistencies with
X86_CR4_VMXE.
As we also had bug reports related to clearing of vmcs with vmm_exclusive=0
this seems to be pretty much untested. So let's better drop it.
While at it, directly move setting/clearing X86_CR4_VMXE into
kvm_cpu_vmxon/off.
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 38 +++++++-------------------------------
1 file changed, 7 insertions(+), 31 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 283aa86..bbbfe12 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -84,9 +84,6 @@ module_param_named(eptad, enable_ept_ad_bits, bool, S_IRUGO);
static bool __read_mostly emulate_invalid_guest_state = true;
module_param(emulate_invalid_guest_state, bool, S_IRUGO);
-static bool __read_mostly vmm_exclusive = 1;
-module_param(vmm_exclusive, bool, S_IRUGO);
-
static bool __read_mostly fasteoi = 1;
module_param(fasteoi, bool, S_IRUGO);
@@ -914,8 +911,6 @@ static void nested_release_page_clean(struct page *page)
static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu);
static u64 construct_eptp(unsigned long root_hpa);
-static void kvm_cpu_vmxon(u64 addr);
-static void kvm_cpu_vmxoff(void);
static bool vmx_xsaves_supported(void);
static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);
static void vmx_set_segment(struct kvm_vcpu *vcpu,
@@ -2235,15 +2230,10 @@ static void decache_tsc_multiplier(struct vcpu_vmx *vmx)
static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
- u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
bool already_loaded = vmx->loaded_vmcs->cpu == cpu;
- if (!vmm_exclusive)
- kvm_cpu_vmxon(phys_addr);
- else if (!already_loaded)
- loaded_vmcs_clear(vmx->loaded_vmcs);
-
if (!already_loaded) {
+ loaded_vmcs_clear(vmx->loaded_vmcs);
local_irq_disable();
crash_disable_local_vmclear(cpu);
@@ -2321,11 +2311,6 @@ static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
vmx_vcpu_pi_put(vcpu);
__vmx_load_host_state(to_vmx(vcpu));
- if (!vmm_exclusive) {
- __loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs);
- vcpu->cpu = -1;
- kvm_cpu_vmxoff();
- }
}
static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);
@@ -3416,6 +3401,7 @@ static __init int vmx_disabled_by_bios(void)
static void kvm_cpu_vmxon(u64 addr)
{
+ cr4_set_bits(X86_CR4_VMXE);
intel_pt_handle_vmx(1);
asm volatile (ASM_VMX_VMXON_RAX
@@ -3458,12 +3444,8 @@ static int hardware_enable(void)
/* enable and lock */
wrmsrl(MSR_IA32_FEATURE_CONTROL, old | test_bits);
}
- cr4_set_bits(X86_CR4_VMXE);
-
- if (vmm_exclusive) {
- kvm_cpu_vmxon(phys_addr);
- ept_sync_global();
- }
+ kvm_cpu_vmxon(phys_addr);
+ ept_sync_global();
native_store_gdt(this_cpu_ptr(&host_gdt));
@@ -3489,15 +3471,13 @@ static void kvm_cpu_vmxoff(void)
asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc");
intel_pt_handle_vmx(0);
+ cr4_clear_bits(X86_CR4_VMXE);
}
static void hardware_disable(void)
{
- if (vmm_exclusive) {
- vmclear_local_loaded_vmcss();
- kvm_cpu_vmxoff();
- }
- cr4_clear_bits(X86_CR4_VMXE);
+ vmclear_local_loaded_vmcss();
+ kvm_cpu_vmxoff();
}
static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
@@ -9228,11 +9208,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
vmx->loaded_vmcs->shadow_vmcs = NULL;
if (!vmx->loaded_vmcs->vmcs)
goto free_msrs;
- if (!vmm_exclusive)
- kvm_cpu_vmxon(__pa(per_cpu(vmxarea, raw_smp_processor_id())));
loaded_vmcs_init(vmx->loaded_vmcs);
- if (!vmm_exclusive)
- kvm_cpu_vmxoff();
cpu = get_cpu();
vmx_vcpu_load(&vmx->vcpu, cpu);
--
2.9.3
