[xen master] x86/hvm: print valid CR4 bits in case of error

[patchbot@xxxxxxx]

commit 6915a120641b5d232762af7882266048cf039ca0
Author:     Roger Pau Monne <roger.pau@xxxxxxxxxx>
AuthorDate: Thu Jun 8 11:59:39 2023 +0200
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Jun 8 11:48:53 2023 +0100

    x86/hvm: print valid CR4 bits in case of error
    
    Some of the current users of hvm_cr4_guest_valid_bits() don't print
    the valid mask in case of error, and thus the resulting error messages
    are not as helpful as they could be.
    
    Amend callers to always print the value of hvm_cr4_guest_valid_bits()
    together with the rejected bits in the checked value. Also take the
    opportunity and adjust all the users to use the same print formatter.
    
    No functional change intended.
    
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/hvm/domain.c       |  9 ++++++---
 xen/arch/x86/hvm/hvm.c          | 17 +++++++++--------
 xen/arch/x86/hvm/svm/svmdebug.c |  4 ++--
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/xen/arch/x86/hvm/domain.c b/xen/arch/x86/hvm/domain.c
index deec74fdb4..7692ee24c2 100644
--- a/xen/arch/x86/hvm/domain.c
+++ b/xen/arch/x86/hvm/domain.c
@@ -107,6 +107,7 @@ int arch_set_info_hvm_guest(struct vcpu *v, const 
vcpu_hvm_context_t *ctx)
     struct segment_register cs, ds, ss, es, tr;
     const char *errstr;
     int rc;
+    unsigned long valid;
 
     if ( ctx->pad != 0 )
         return -EINVAL;
@@ -264,10 +265,12 @@ 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) )
+    valid = hvm_cr4_guest_valid_bits(d);
+    if ( v->arch.hvm.guest_cr[4] & ~valid )
     {
-        gprintk(XENLOG_ERR, "Bad CR4 value: %#016lx\n",
-                v->arch.hvm.guest_cr[4]);
+        gprintk(XENLOG_ERR, "Bad CR4 %#lx (valid %#lx, rejected %#lx)\n",
+                v->arch.hvm.guest_cr[4], valid,
+                v->arch.hvm.guest_cr[4] & ~valid);
         return -EINVAL;
     }
 
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 2d6e4bb9c6..a67ef79dc0 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -991,6 +991,7 @@ static int cf_check hvm_load_cpu_ctxt(struct domain *d, 
hvm_domain_context_t *h)
     struct hvm_hw_cpu ctxt;
     struct segment_register seg;
     const char *errstr;
+    unsigned long valid;
 
     /* Which vcpu is this? */
     if ( vcpuid >= d->max_vcpus || (v = d->vcpu[vcpuid]) == NULL )
@@ -1016,10 +1017,11 @@ static int cf_check hvm_load_cpu_ctxt(struct domain *d, 
hvm_domain_context_t *h)
         return -EINVAL;
     }
 
-    if ( ctxt.cr4 & ~hvm_cr4_guest_valid_bits(d) )
+    valid = hvm_cr4_guest_valid_bits(d);
+    if ( ctxt.cr4 & ~valid )
     {
-        printk(XENLOG_G_ERR "HVM%d restore: bad CR4 %#" PRIx64 "\n",
-               d->domain_id, ctxt.cr4);
+        printk(XENLOG_G_ERR "HVM%d restore: bad CR4 %#lx (valid %#lx, rejected 
%#lx)\n",
+               d->domain_id, ctxt.cr4, valid, ctxt.cr4 & ~valid);
         return -EINVAL;
     }
 
@@ -2456,13 +2458,12 @@ int hvm_set_cr3(unsigned long value, bool noflush, bool 
may_defer)
 int hvm_set_cr4(unsigned long value, bool may_defer)
 {
     struct vcpu *v = current;
-    unsigned long old_cr;
+    unsigned long old_cr, valid = hvm_cr4_guest_valid_bits(v->domain);
 
-    if ( value & ~hvm_cr4_guest_valid_bits(v->domain) )
+    if ( value & ~valid )
     {
-        HVM_DBG_LOG(DBG_LEVEL_1,
-                    "Guest attempts to set reserved bit in CR4: %lx",
-                    value);
+        HVM_DBG_LOG(DBG_LEVEL_1, "Bad CR4 %#lx (valid %#lx, rejected %#lx)",
+                    value, valid, value & ~valid);
         return X86EMUL_EXCEPTION;
     }
 
diff --git a/xen/arch/x86/hvm/svm/svmdebug.c b/xen/arch/x86/hvm/svm/svmdebug.c
index 7d6dc9ef47..24358c6eea 100644
--- a/xen/arch/x86/hvm/svm/svmdebug.c
+++ b/xen/arch/x86/hvm/svm/svmdebug.c
@@ -124,8 +124,8 @@ bool svm_vmcb_isvalid(const char *from, const struct 
vmcb_struct *vmcb,
 
     valid = hvm_cr4_guest_valid_bits(v->domain);
     if ( cr4 & ~valid )
-        PRINTF("CR4: invalid bits are set (%#"PRIx64", valid: %#"PRIx64")\n",
-               cr4, valid);
+        PRINTF("CR4: invalid value %#lx (valid %#lx, rejected %#lx)\n",
+               cr4, valid, cr4 & ~valid);
 
     if ( vmcb_get_dr6(vmcb) >> 32 )
         PRINTF("DR6: bits [63:32] are not zero (%#"PRIx64")\n",
--
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