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Mathias Krause
fb509f76ac
Guests like grsecurity that make heavy use of CR0.WP to implement kernel level W^X will suffer from the implied VMEXITs. With EPT there is no need to intercept a guest change of CR0.WP, so simply make it a guest owned bit if we can do so. This implies that a read of a guest's CR0.WP bit might need a VMREAD. However, the only potentially affected user seems to be kvm_init_mmu() which is a heavy operation to begin with. But also most callers already cache the full value of CR0 anyway, so no additional VMREAD is needed. The only exception is nested_vmx_load_cr3(). This change is VMX-specific, as SVM has no such fine grained control register intercept control. Suggested-by: Sean Christopherson <[email protected]> Signed-off-by: Mathias Krause <[email protected]> Link: https://lore.kernel.org/r/[email protected] Co-developed-by: Sean Christopherson <[email protected]> Signed-off-by: Sean Christopherson <[email protected]>