[PATCH 7/8] x86/hvm: Drop restore boolean from hvm_cr4_guest_valid_bits()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Previously, migration was reordered so the CPUID data was available before
register state.  nestedhvm_enabled() has recently been made accurate for the
entire lifetime of the domain.

Therefore, we can drop the bodge in hvm_cr4_guest_valid_bits() which existed
previously to tolerate a guests' CR4 being set/restored before
HVM_PARAM_NESTEDHVM.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Jun Nakajima <jun.nakajima@xxxxxxxxx>
CC: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/arch/x86/hvm/domain.c       | 2 +-
 xen/arch/x86/hvm/hvm.c          | 8 ++++----
 xen/arch/x86/hvm/svm/svmdebug.c | 6 ++++--
 xen/arch/x86/hvm/vmx/vmx.c      | 2 +-
 xen/arch/x86/hvm/vmx/vvmx.c     | 2 +-
 xen/include/asm-x86/hvm/hvm.h   | 2 +-
 6 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/xen/arch/x86/hvm/domain.c b/xen/arch/x86/hvm/domain.c
index 8e3375265c..0ce132b308 100644
--- a/xen/arch/x86/hvm/domain.c
+++ b/xen/arch/x86/hvm/domain.c
@@ -275,7 +275,7 @@ int arch_set_info_hvm_guest(struct vcpu *v, const 
vcpu_hvm_context_t *ctx)
     if ( v->arch.hvm.guest_efer & EFER_LME )
         v->arch.hvm.guest_efer |= EFER_LMA;
 
-    if ( v->arch.hvm.guest_cr[4] & ~hvm_cr4_guest_valid_bits(d, false) )
+    if ( v->arch.hvm.guest_cr[4] & ~hvm_cr4_guest_valid_bits(d) )
     {
         gprintk(XENLOG_ERR, "Bad CR4 value: %#016lx\n",
                 v->arch.hvm.guest_cr[4]);
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 101a739952..54e32e4fe8 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -972,14 +972,14 @@ const char *hvm_efer_valid(const struct vcpu *v, uint64_t 
value,
         X86_CR0_CD | X86_CR0_PG)))
 
 /* These bits in CR4 can be set by the guest. */
-unsigned long hvm_cr4_guest_valid_bits(const struct domain *d, bool restore)
+unsigned long hvm_cr4_guest_valid_bits(const struct domain *d)
 {
     const struct cpuid_policy *p = d->arch.cpuid;
     bool mce, vmxe;
 
     /* Logic broken out simply to aid readability below. */
     mce  = p->basic.mce || p->basic.mca;
-    vmxe = p->basic.vmx && (restore || nestedhvm_enabled(d));
+    vmxe = p->basic.vmx && nestedhvm_enabled(d);
 
     return ((p->basic.vme     ? X86_CR4_VME | X86_CR4_PVI : 0) |
             (p->basic.tsc     ? X86_CR4_TSD               : 0) |
@@ -1033,7 +1033,7 @@ static int hvm_load_cpu_ctxt(struct domain *d, 
hvm_domain_context_t *h)
         return -EINVAL;
     }
 
-    if ( ctxt.cr4 & ~hvm_cr4_guest_valid_bits(d, true) )
+    if ( ctxt.cr4 & ~hvm_cr4_guest_valid_bits(d) )
     {
         printk(XENLOG_G_ERR "HVM%d restore: bad CR4 %#" PRIx64 "\n",
                d->domain_id, ctxt.cr4);
@@ -2425,7 +2425,7 @@ int hvm_set_cr4(unsigned long value, bool may_defer)
     struct vcpu *v = current;
     unsigned long old_cr;
 
-    if ( value & ~hvm_cr4_guest_valid_bits(v->domain, false) )
+    if ( value & ~hvm_cr4_guest_valid_bits(v->domain) )
     {
         HVM_DBG_LOG(DBG_LEVEL_1,
                     "Guest attempts to set reserved bit in CR4: %lx",
diff --git a/xen/arch/x86/hvm/svm/svmdebug.c b/xen/arch/x86/hvm/svm/svmdebug.c
index ba26b6a80b..f450391df4 100644
--- a/xen/arch/x86/hvm/svm/svmdebug.c
+++ b/xen/arch/x86/hvm/svm/svmdebug.c
@@ -106,6 +106,7 @@ bool svm_vmcb_isvalid(const char *from, const struct 
vmcb_struct *vmcb,
     unsigned long cr0 = vmcb_get_cr0(vmcb);
     unsigned long cr3 = vmcb_get_cr3(vmcb);
     unsigned long cr4 = vmcb_get_cr4(vmcb);
+    unsigned long valid;
     uint64_t efer = vmcb_get_efer(vmcb);
 
 #define PRINTF(fmt, args...) do { \
@@ -130,9 +131,10 @@ bool svm_vmcb_isvalid(const char *from, const struct 
vmcb_struct *vmcb,
            (cr3 >> v->domain->arch.cpuid->extd.maxphysaddr))) )
         PRINTF("CR3: MBZ bits are set (%#"PRIx64")\n", cr3);
 
-    if ( cr4 & ~hvm_cr4_guest_valid_bits(v->domain, false) )
+    valid = hvm_cr4_guest_valid_bits(v->domain);
+    if ( cr4 & ~valid )
         PRINTF("CR4: invalid bits are set (%#"PRIx64", valid: %#"PRIx64")\n",
-               cr4, hvm_cr4_guest_valid_bits(v->domain, false));
+               cr4, valid);
 
     if ( vmcb_get_dr6(vmcb) >> 32 )
         PRINTF("DR6: bits [63:32] are not zero (%#"PRIx64")\n",
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 95d109f962..86b8916a5d 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1529,7 +1529,7 @@ static void vmx_update_guest_cr(struct vcpu *v, unsigned 
int cr,
              */
             v->arch.hvm.vmx.cr4_host_mask =
                 (HVM_CR4_HOST_MASK | X86_CR4_PKE |
-                 ~hvm_cr4_guest_valid_bits(v->domain, false));
+                 ~hvm_cr4_guest_valid_bits(v->domain));
 
             v->arch.hvm.vmx.cr4_host_mask |= v->arch.hvm.vmx.vmx_realmode ?
                                              X86_CR4_VME : 0;
diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 1e51689ef3..3a37e9ebea 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -2323,7 +2323,7 @@ int nvmx_msr_read_intercept(unsigned int msr, u64 
*msr_content)
         data = X86_CR4_VMXE;
         break;
     case MSR_IA32_VMX_CR4_FIXED1:
-        data = hvm_cr4_guest_valid_bits(d, false);
+        data = hvm_cr4_guest_valid_bits(d);
         break;
     case MSR_IA32_VMX_MISC:
         /* Do not support CR3-target feature now */
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index be0d8b0a4d..334bd573b9 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -334,7 +334,7 @@ int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long 
gla,
 /* Check CR4/EFER values */
 const char *hvm_efer_valid(const struct vcpu *v, uint64_t value,
                            signed int cr0_pg);
-unsigned long hvm_cr4_guest_valid_bits(const struct domain *d, bool restore);
+unsigned long hvm_cr4_guest_valid_bits(const struct domain *d);
 
 int hvm_copy_context_and_params(struct domain *src, struct domain *dst);
 
-- 
2.11.0