[SRU Bionic] Revert "KVM: x86: Manually calculate reserved bits when loading PDPTRS"

[Thadeu Lima de Souza Cascardo]

BugLink: https://bugs.launchpad.net/bugs/1851709

This reverts commit c5d574d63996442c80e886c60278a790230f4d2b.

This commit has caused failure to launch 64-bit linux VMs when kvm-intel
ept module parameter is off. It is off by default on old Intel CPUs.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
---
 arch/x86/kvm/x86.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ddbd7578ae25..d59095ab1f1c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -566,14 +566,8 @@ static int kvm_read_nested_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
 				       data, offset, len, access);
 }
 
-static inline u64 pdptr_rsvd_bits(struct kvm_vcpu *vcpu)
-{
-	return rsvd_bits(cpuid_maxphyaddr(vcpu), 63) | rsvd_bits(5, 8) |
-	       rsvd_bits(1, 2);
-}
-
 /*
- * Load the pae pdptrs.  Return 1 if they are all valid, 0 otherwise.
+ * Load the pae pdptrs.  Return true is they are all valid.
  */
 int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
 {
@@ -592,7 +586,8 @@ int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
 	}
 	for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
 		if ((pdpte[i] & PT_PRESENT_MASK) &&
-		    (pdpte[i] & pdptr_rsvd_bits(vcpu))) {
+		    (pdpte[i] &
+		     vcpu->arch.mmu.guest_rsvd_check.rsvd_bits_mask[0][2])) {
 			ret = 0;
 			goto out;
 		}
-- 
2.20.1