[PATCH 040/104] KVM: VMX: Add cpu consistency check

Avi Kivity
2007-09-17T08:39:55Z

From: Yang, Sheng <sheng.yang@intel.com>

All the physical CPUs on the board should support the same VMX feature
set. Add check_processor_compatibility to kvm_arch_ops for the consistency
check.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
drivers/kvm/kvm.h | 1 +
drivers/kvm/kvm_main.c | 10 +++++++++
drivers/kvm/svm.c | 6 +++++
drivers/kvm/vmx.c | 51 +++++++++++++++++++++++++++++++----------------
4 files changed, 50 insertions(+), 18 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 7a34706..cfda3ab 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -420,6 +420,7 @@ struct kvm_arch_ops {
int (*disabled_by_bios)(void); /* __init */
void (*hardware_enable)(void *dummy); /* __init */
void (*hardware_disable)(void *dummy);
+ void (*check_processor_compatibility)(void *rtn);
int (*hardware_setup)(void); /* __init */
void (*hardware_unsetup)(void); /* __exit */

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 5dee302..2be6b1c 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -3102,6 +3102,7 @@ int kvm_init_arch(struct kvm_arch_ops *ops, unsigned int vcpu_size,
struct module *module)
{
int r;
+ int cpu;

if (kvm_arch_ops) {
printk(KERN_ERR "kvm: already loaded the other module\n");
@@ -3123,6 +3124,14 @@ int kvm_init_arch(struct kvm_arch_ops *ops, unsigned int vcpu_size,
if (r < 0)
goto out;

+ for_each_online_cpu(cpu) {
+ smp_call_function_single(cpu,
+ kvm_arch_ops->check_processor_compatibility,
+ &r, 0, 1);
+ if (r < 0)
+ goto out_free_0;
+ }
+
on_each_cpu(hardware_enable, NULL, 0, 1);
r = register_cpu_notifier(&kvm_cpu_notifier);
if (r)
@@ -3169,6 +3178,7 @@ out_free_2:
unregister_cpu_notifier(&kvm_cpu_notifier);
out_free_1:
on_each_cpu(hardware_disable, NULL, 0, 1);
+out_free_0:
kvm_arch_ops->hardware_unsetup();
out:
kvm_arch_ops = NULL;
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 5277084..827bc27 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1798,11 +1798,17 @@ svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
hypercall[3] = 0xc3;
}

+static void svm_check_processor_compat(void *rtn)
+{
+ *(int *)rtn = 0;
+}
+
static struct kvm_arch_ops svm_arch_ops = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
.hardware_setup = svm_hardware_setup,
.hardware_unsetup = svm_hardware_unsetup,
+ .check_processor_compatibility = svm_check_processor_compat,
.hardware_enable = svm_hardware_enable,
.hardware_disable = svm_hardware_disable,

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 2b30274..c4b8bfe 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -840,13 +840,13 @@ static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,

/* Ensure minimum (required) set of control bits are supported. */
if (ctl_min & ~ctl)
- return -1;
+ return -EIO;

*result = ctl;
return 0;
}

-static __init int setup_vmcs_config(void)
+static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
{
u32 vmx_msr_low, vmx_msr_high;
u32 min, opt;
@@ -859,7 +859,7 @@ static __init int setup_vmcs_config(void)
opt = 0;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PINBASED_CTLS,
&_pin_based_exec_control) < 0)
- return -1;
+ return -EIO;

min = CPU_BASED_HLT_EXITING |
#ifdef CONFIG_X86_64
@@ -872,7 +872,7 @@ static __init int setup_vmcs_config(void)
opt = 0;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
&_cpu_based_exec_control) < 0)
- return -1;
+ return -EIO;

min = 0;
#ifdef CONFIG_X86_64
@@ -881,37 +881,37 @@ static __init int setup_vmcs_config(void)
opt = 0;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
&_vmexit_control) < 0)
- return -1;
+ return -EIO;

min = opt = 0;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS,
&_vmentry_control) < 0)
- return -1;
+ return -EIO;

rdmsr(MSR_IA32_VMX_BASIC, vmx_msr_low, vmx_msr_high);

/* IA-32 SDM Vol 3B: VMCS size is never greater than 4kB. */
if ((vmx_msr_high & 0x1fff) > PAGE_SIZE)
- return -1;
+ return -EIO;

#ifdef CONFIG_X86_64
/* IA-32 SDM Vol 3B: 64-bit CPUs always have VMX_BASIC_MSR[48]==0. */
if (vmx_msr_high & (1u<<16))
- return -1;
+ return -EIO;
#endif

/* Require Write-Back (WB) memory type for VMCS accesses. */
if (((vmx_msr_high >> 18) & 15) != 6)
- return -1;
+ return -EIO;

- vmcs_config.size = vmx_msr_high & 0x1fff;
- vmcs_config.order = get_order(vmcs_config.size);
- vmcs_config.revision_id = vmx_msr_low;
+ vmcs_conf->size = vmx_msr_high & 0x1fff;
+ vmcs_conf->order = get_order(vmcs_config.size);
+ vmcs_conf->revision_id = vmx_msr_low;

- vmcs_config.pin_based_exec_ctrl = _pin_based_exec_control;
- vmcs_config.cpu_based_exec_ctrl = _cpu_based_exec_control;
- vmcs_config.vmexit_ctrl = _vmexit_control;
- vmcs_config.vmentry_ctrl = _vmentry_control;
+ vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
+ vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
+ vmcs_conf->vmexit_ctrl = _vmexit_control;
+ vmcs_conf->vmentry_ctrl = _vmentry_control;

return 0;
}
@@ -971,8 +971,8 @@ static __init int alloc_kvm_area(void)

static __init int hardware_setup(void)
{
- if (setup_vmcs_config() < 0)
- return -1;
+ if (setup_vmcs_config(&vmcs_config) < 0)
+ return -EIO;
return alloc_kvm_area();
}

@@ -2414,11 +2414,26 @@ free_vcpu:
return ERR_PTR(err);
}

+static void __init vmx_check_processor_compat(void *rtn)
+{
+ struct vmcs_config vmcs_conf;
+
+ *(int *)rtn = 0;
+ if (setup_vmcs_config(&vmcs_conf) < 0)
+ *(int *)rtn = -EIO;
+ if (memcmp(&vmcs_config, &vmcs_conf, sizeof(struct vmcs_config)) != 0) {
+ printk(KERN_ERR "kvm: CPU %d feature inconsistency!\n",
+ smp_processor_id());
+ *(int *)rtn = -EIO;
+ }
+}
+
static struct kvm_arch_ops vmx_arch_ops = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
.hardware_setup = hardware_setup,
.hardware_unsetup = hardware_unsetup,
+ .check_processor_compatibility = vmx_check_processor_compat,
.hardware_enable = hardware_enable,
.hardware_disable = hardware_disable,

--
1.5.3