[PULL 5/5] hvf: more accurately match SDM when setting CR0 and PDPTE registers

[Paolo Bonzini <pbonzini@redhat.com>]

From: Cameron Esfahani <dirty@apple.com>

More accurately match SDM when setting CR0 and PDPTE registers.

Clear PDPTE registers when resetting vcpus.

Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <464adb39c8699fb8331d8ad6016fc3e2eff53dbc.1574625592.git.dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/hvf/hvf.c |  8 ++++++++
 target/i386/hvf/vmx.h | 18 ++++++++++--------
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c
index 90fd50acfc..784e67d77e 100644
--- a/target/i386/hvf/hvf.c
+++ b/target/i386/hvf/hvf.c
@@ -441,12 +441,20 @@ static MemoryListener hvf_memory_listener = {
 };
 
 void hvf_reset_vcpu(CPUState *cpu) {
+    uint64_t pdpte[4] = {0, 0, 0, 0};
+    int i;
 
     /* TODO: this shouldn't be needed; there is already a call to
      * cpu_synchronize_all_post_reset in vl.c
      */
     wvmcs(cpu->hvf_fd, VMCS_ENTRY_CTLS, 0);
     wvmcs(cpu->hvf_fd, VMCS_GUEST_IA32_EFER, 0);
+
+    /* Initialize PDPTE */
+    for (i = 0; i < 4; i++) {
+        wvmcs(cpu->hvf_fd, VMCS_GUEST_PDPTE0 + i * 2, pdpte[i]);
+    }
+
     macvm_set_cr0(cpu->hvf_fd, 0x60000010);
 
     wvmcs(cpu->hvf_fd, VMCS_CR4_MASK, CR4_VMXE_MASK);
diff --git a/target/i386/hvf/vmx.h b/target/i386/hvf/vmx.h
index 5dc52ecad6..eb8894cd58 100644
--- a/target/i386/hvf/vmx.h
+++ b/target/i386/hvf/vmx.h
@@ -121,6 +121,7 @@ static inline void macvm_set_cr0(hv_vcpuid_t vcpu, uint64_t cr0)
     uint64_t pdpte[4] = {0, 0, 0, 0};
     uint64_t efer = rvmcs(vcpu, VMCS_GUEST_IA32_EFER);
     uint64_t old_cr0 = rvmcs(vcpu, VMCS_GUEST_CR0);
+    uint64_t mask = CR0_PG | CR0_CD | CR0_NW | CR0_NE | CR0_ET;
 
     if ((cr0 & CR0_PG) && (rvmcs(vcpu, VMCS_GUEST_CR4) & CR4_PAE) &&
         !(efer & MSR_EFER_LME)) {
@@ -128,18 +129,15 @@ static inline void macvm_set_cr0(hv_vcpuid_t vcpu, uint64_t cr0)
                          rvmcs(vcpu, VMCS_GUEST_CR3) & ~0x1f,
                          MEMTXATTRS_UNSPECIFIED,
                          (uint8_t *)pdpte, 32, 0);
+        /* Only set PDPTE when appropriate. */
+        for (i = 0; i < 4; i++) {
+            wvmcs(vcpu, VMCS_GUEST_PDPTE0 + i * 2, pdpte[i]);
+        }
     }
 
-    for (i = 0; i < 4; i++) {
-        wvmcs(vcpu, VMCS_GUEST_PDPTE0 + i * 2, pdpte[i]);
-    }
-
-    wvmcs(vcpu, VMCS_CR0_MASK, CR0_CD | CR0_NE | CR0_PG);
+    wvmcs(vcpu, VMCS_CR0_MASK, mask);
     wvmcs(vcpu, VMCS_CR0_SHADOW, cr0);
 
-    cr0 &= ~CR0_CD;
-    wvmcs(vcpu, VMCS_GUEST_CR0, cr0 | CR0_NE | CR0_ET);
-
     if (efer & MSR_EFER_LME) {
         if (!(old_cr0 & CR0_PG) && (cr0 & CR0_PG)) {
             enter_long_mode(vcpu, cr0, efer);
@@ -149,6 +147,10 @@ static inline void macvm_set_cr0(hv_vcpuid_t vcpu, uint64_t cr0)
         }
     }
 
+    /* Filter new CR0 after we are finished examining it above. */
+    cr0 = (cr0 & ~(mask & ~CR0_PG));
+    wvmcs(vcpu, VMCS_GUEST_CR0, cr0 | CR0_NE | CR0_ET);
+
     hv_vcpu_invalidate_tlb(vcpu);
     hv_vcpu_flush(vcpu);
 }
-- 
2.21.0