[PATCH 23/43] KVM: VMX: Fold ept_update_paging_mode_cr0() back into vmx_set_cr0()

From: Sean Christopherson
Date: Fri Apr 23 2021 - 20:52:07 EST


Move the CR0/CR3/CR4 shenanigans for EPT without unrestricted guest back
into vmx_set_cr0(). This will allow a future patch to eliminate the
rather gross stuffing of vcpu->arch.cr0 in the paging transition cases
by snapshotting the old CR0.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 40 +++++++++++++++++-----------------------
1 file changed, 17 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5795de909609..c9322cd55390 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3102,27 +3102,6 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu)
kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
}

-static void ept_update_paging_mode_cr0(unsigned long cr0, struct kvm_vcpu *vcpu)
-{
- struct vcpu_vmx *vmx = to_vmx(vcpu);
-
- if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
- vmx_cache_reg(vcpu, VCPU_EXREG_CR3);
- if (!(cr0 & X86_CR0_PG)) {
- /* From paging/starting to nonpaging */
- exec_controls_setbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
- CPU_BASED_CR3_STORE_EXITING);
- vcpu->arch.cr0 = cr0;
- vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
- } else if (!is_paging(vcpu)) {
- /* From nonpaging to paging */
- exec_controls_clearbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
- CPU_BASED_CR3_STORE_EXITING);
- vcpu->arch.cr0 = cr0;
- vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
- }
-}
-
void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -3152,8 +3131,23 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
}
#endif

- if (enable_ept && !is_unrestricted_guest(vcpu))
- ept_update_paging_mode_cr0(cr0, vcpu);
+ if (enable_ept && !is_unrestricted_guest(vcpu)) {
+ if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
+ vmx_cache_reg(vcpu, VCPU_EXREG_CR3);
+ if (!(cr0 & X86_CR0_PG)) {
+ /* From paging/starting to nonpaging */
+ exec_controls_setbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
+ CPU_BASED_CR3_STORE_EXITING);
+ vcpu->arch.cr0 = cr0;
+ vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
+ } else if (!is_paging(vcpu)) {
+ /* From nonpaging to paging */
+ exec_controls_clearbit(vmx, CPU_BASED_CR3_LOAD_EXITING |
+ CPU_BASED_CR3_STORE_EXITING);
+ vcpu->arch.cr0 = cr0;
+ vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
+ }
+ }

vmcs_writel(CR0_READ_SHADOW, cr0);
vmcs_writel(GUEST_CR0, hw_cr0);
--
2.31.1.498.g6c1eba8ee3d-goog