[PATCH 14/15] kvm: vmx: crash_hardware_disable function

Eduardo Habkost
2008-11-05T19:56:57Z

We need to first check if virtualization was enabled. We do this by
checking CR4.VMXE. If it is set, run vmxoff and clear CR4.VMXE.

Register it using set_virt_disable_func() on hardware_setup, and
unregister it on hardware_unsetup.

Signed-off-by: Eduardo Habkost <ehabkost-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
arch/x86/kvm/vmx.c | 40 +++++++++++++++++++++++++++++++++++-----
1 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ece9cb7..4b10768 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -31,6 +31,7 @@

#include <asm/io.h>
#include <asm/desc.h>
+#include <asm/virtext.h>

#define __ex(x) __kvm_handle_fault_on_reboot(x)

@@ -1091,13 +1092,24 @@ static void vmclear_local_vcpus(void)
__vcpu_clear(vmx);
}

-static void hardware_disable(void *garbage)
+static void __hardware_disable(void)
{
- vmclear_local_vcpus();
asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc");
write_cr4(read_cr4() & ~X86_CR4_VMXE);
}

+static void hardware_disable(void *garbage)
+{
+ vmclear_local_vcpus();
+ __hardware_disable();
+}
+
+static void crash_hardware_disable(void)
+{
+ if (read_cr4() & X86_CR4_VMXE)
+ __hardware_disable();
+}
+
static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
u32 msr, u32 *result)
{
@@ -1281,18 +1293,36 @@ static __init int alloc_kvm_area(void)

static __init int hardware_setup(void)
{
- if (setup_vmcs_config(&vmcs_config) < 0)
- return -EIO;
+ int r;
+
+ r = set_virt_disable_func(crash_hardware_disable);
+ if (r)
+ goto err;
+
+ if (setup_vmcs_config(&vmcs_config) < 0) {
+ r = -EIO;
+ goto err_clear_virt_disable;
+ }

if (boot_cpu_has(X86_FEATURE_NX))
kvm_enable_efer_bits(EFER_NX);

- return alloc_kvm_area();
+ r = alloc_kvm_area();
+ if (r)
+ goto err_clear_virt_disable;
+
+ return 0;
+
+err_clear_virt_disable:
+ clear_virt_disable_func();
+err:
+ return r;
}

static __exit void hardware_unsetup(void)
{
free_kvm_area();
+ clear_virt_disable_func();
}

static void fix_pmode_dataseg(int seg, struct kvm_save_segment *save)
--
1.5.5.GIT