x86/mce: translate passed-in GPA to host machine address

This patch adds a new flag MC_MSRINJ_F_GPADDR to
xen_mc_msrinject.mcinj_flags, and makes do_mca() to translate the
guest physical address passed-in through
xen_mc_msrinject.mcinj_msr[i].value to the host machine address if
this flag is present.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Acked-by: Christoph Egger <chegger@amazon.de>

xen/arch/x86/cpu/mcheck/mce.c

@@ -21,6 +21,7 @@
 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/msr.h>
+#include <asm/p2m.h>
 
 #include "mce.h"
 #include "barrier.h"
@@ -48,14 +49,15 @@ struct mca_banks *mca_allbanks;
 #define _MC_MSRINJ_F_REQ_HWCR_WREN (1 << 16)
 
 #if 0
-static int x86_mcerr(const char *msg, int err)
-{
-    gdprintk(XENLOG_WARNING, "x86_mcerr: %s, returning %d\n",
-             msg != NULL ? msg : "", err);
-    return err;
-}
+#define x86_mcerr(fmt, err, args...)                                    \
+    ({                                                                  \
+        int _err = (err);                                               \
+        gdprintk(XENLOG_WARNING, "x86_mcerr: " fmt ", returning %d\n",  \
+                 ## args, _err);                                        \
+        _err;                                                           \
+    })
 #else
-#define x86_mcerr(msg, err) (err)
+#define x86_mcerr(fmt, err, args...) (err)
 #endif
 
 int mce_verbosity;
@@ -1307,7 +1309,7 @@ long do_mca(XEN_GUEST_HANDLE_PARAM(xen_mc_t) u_xen_mc)
 
     ret = xsm_do_mca(XSM_PRIV);
     if ( ret )
-        return x86_mcerr(NULL, ret);
+        return x86_mcerr("", ret);
 
     if ( copy_from_guest(op, u_xen_mc, 1) )
         return x86_mcerr("do_mca: failed copyin of xen_mc_t", -EFAULT);
@@ -1422,6 +1424,44 @@ long do_mca(XEN_GUEST_HANDLE_PARAM(xen_mc_t) u_xen_mc)
         if (mc_msrinject->mcinj_count == 0)
             return 0;
 
+        if ( mc_msrinject->mcinj_flags & MC_MSRINJ_F_GPADDR )
+        {
+            struct domain *d;
+            struct mcinfo_msr *msr;
+            unsigned int i;
+            paddr_t gaddr;
+            unsigned long gfn, mfn;
+            p2m_type_t t;
+
+            d = get_domain_by_id(mc_msrinject->mcinj_domid);
+            if ( d == NULL )
+                return x86_mcerr("do_mca inject: bad domain id %d",
+                                 -EINVAL, mc_msrinject->mcinj_domid);
+
+            for ( i = 0, msr = &mc_msrinject->mcinj_msr[0];
+                  i < mc_msrinject->mcinj_count;
+                  i++, msr++ )
+            {
+                gaddr = msr->value;
+                gfn = PFN_DOWN(gaddr);
+                mfn = mfn_x(get_gfn(d, gfn, &t));
+
+                if ( mfn == INVALID_MFN )
+                {
+                    put_gfn(d, gfn);
+                    put_domain(d);
+                    return x86_mcerr("do_mca inject: bad gfn %#lx of domain %d",
+                                     -EINVAL, gfn, mc_msrinject->mcinj_domid);
+                }
+
+                msr->value = pfn_to_paddr(mfn) | (gaddr & (PAGE_SIZE - 1));
+
+                put_gfn(d, gfn);
+            }
+
+            put_domain(d);
+        }
+
         if (!x86_mc_msrinject_verify(mc_msrinject))
             return x86_mcerr("do_mca inject: illegal MSR", -EINVAL);
 

xen/include/public/arch-x86/xen-mca.h

@@ -392,12 +392,15 @@ struct xen_mc_msrinject {
     uint32_t mcinj_cpunr;           /* target processor id */
     uint32_t mcinj_flags;           /* see MC_MSRINJ_F_* below */
     uint32_t mcinj_count;           /* 0 .. count-1 in array are valid */
-    uint32_t _pad0;
+    domid_t  mcinj_domid;           /* valid only if MC_MSRINJ_F_GPADDR is
+                                       present in mcinj_flags */
+    uint16_t _pad0;
     struct mcinfo_msr mcinj_msr[MC_MSRINJ_MAXMSRS];
 };
 
 /* Flags for mcinj_flags above; bits 16-31 are reserved */
 #define MC_MSRINJ_F_INTERPOSE   0x1
+#define MC_MSRINJ_F_GPADDR      0x2
 
 #define XEN_MC_mceinject    5
 struct xen_mc_mceinject {