[PATCH v2 30/50] KVM: VMX: Make VMCS configuration/capabilities structs read-only after init

From: Sean Christopherson
Date: Wed Nov 30 2022 - 18:14:48 EST


Tag vmcs_config and vmx_capability structs as __init, the canonical
configuration is generated during hardware_setup() and must never be
modified after that point.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/capabilities.h | 4 ++--
arch/x86/kvm/vmx/vmx.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index cd2ac9536c99..45162c1bcd8f 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -66,13 +66,13 @@ struct vmcs_config {
u64 misc;
struct nested_vmx_msrs nested;
};
-extern struct vmcs_config vmcs_config;
+extern struct vmcs_config vmcs_config __ro_after_init;

struct vmx_capability {
u32 ept;
u32 vpid;
};
-extern struct vmx_capability vmx_capability;
+extern struct vmx_capability vmx_capability __ro_after_init;

static inline bool cpu_has_vmx_basic_inout(void)
{
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 76185a7a7ded..654d81f781da 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -488,8 +488,8 @@ static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu);
static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
static DEFINE_SPINLOCK(vmx_vpid_lock);

-struct vmcs_config vmcs_config;
-struct vmx_capability vmx_capability;
+struct vmcs_config vmcs_config __ro_after_init;
+struct vmx_capability vmx_capability __ro_after_init;

#define VMX_SEGMENT_FIELD(seg) \
[VCPU_SREG_##seg] = { \
--
2.38.1.584.g0f3c55d4c2-goog