x86/mce: Mask out non-address bits from machine check bank

Systems that support various memory encryption schemes (MKTME, TDX, SEV)
use high order physical address bits to indicate which key should be
used for a specific memory location.

When a memory error is reported, some systems may report those key
bits in the IA32_MCi_ADDR machine check MSR.

The Intel SDM has a footnote for the contents of the address register
that says: "Useful bits in this field depend on the address methodology
in use when the register state is saved."

AMD Processor Programming Reference has a more explicit description
of the MCA_ADDR register:

 "For physical addresses, the most significant bit is given by
  Core::X86::Cpuid::LongModeInfo[PhysAddrSize]."

Add a new #define MCI_ADDR_PHYSADDR for the mask of valid physical
address bits within the machine check bank address register. Use this
mask for recoverable machine check handling and in the EDAC driver to
ignore any key bits that may be present.

  [ Tony: Based on independent fixes proposed by Fan Du and Isaku Yamahata ]

Reported-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reported-by: Fan Du <fan.du@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: https://lore.kernel.org/r/20230109152936.397862-1-tony.luck@intel.com

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 6e986088817d510be6e957247533495f2b5594d8..9646ed6e8c0b95318ab65e19dd261ec3c34ba55e 100644 (file)
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -88,6 +88,9 @@
 #define  MCI_MISC_ADDR_MEM     3       /* memory address */
 #define  MCI_MISC_ADDR_GENERIC 7       /* generic */
 
+/* MCi_ADDR register defines */
+#define MCI_ADDR_PHYSADDR      GENMASK_ULL(boot_cpu_data.x86_phys_bits - 1, 0)
+
 /* CTL2 register defines */
 #define MCI_CTL2_CMCI_EN               BIT_ULL(30)
 #define MCI_CTL2_CMCI_THRESHOLD_MASK   0x7fffULL

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 626a1c666252dd2b4ec68fd6fd6bfc7435c3af43..7832a69d170e723c1088098606d9f7b9796d1a94 100644 (file)
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -573,7 +573,7 @@ static int uc_decode_notifier(struct notifier_block *nb, unsigned long val,
            mce->severity != MCE_DEFERRED_SEVERITY)
                return NOTIFY_DONE;
 
-       pfn = mce->addr >> PAGE_SHIFT;
+       pfn = (mce->addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT;
        if (!memory_failure(pfn, 0)) {
                set_mce_nospec(pfn);
                mce->kflags |= MCE_HANDLED_UC;
@@ -1294,6 +1294,7 @@ static void kill_me_maybe(struct callback_head *cb)
 {
        struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me);
        int flags = MF_ACTION_REQUIRED;
+       unsigned long pfn;
        int ret;
 
        p->mce_count = 0;
@@ -1302,9 +1303,10 @@ static void kill_me_maybe(struct callback_head *cb)
        if (!p->mce_ripv)
                flags |= MF_MUST_KILL;
 
-       ret = memory_failure(p->mce_addr >> PAGE_SHIFT, flags);
+       pfn = (p->mce_addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT;
+       ret = memory_failure(pfn, flags);
        if (!ret) {
-               set_mce_nospec(p->mce_addr >> PAGE_SHIFT);
+               set_mce_nospec(pfn);
                sync_core();
                return;
        }
@@ -1326,11 +1328,13 @@ static void kill_me_maybe(struct callback_head *cb)
 static void kill_me_never(struct callback_head *cb)
 {
        struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me);
+       unsigned long pfn;
 
        p->mce_count = 0;
        pr_err("Kernel accessed poison in user space at %llx\n", p->mce_addr);
-       if (!memory_failure(p->mce_addr >> PAGE_SHIFT, 0))
-               set_mce_nospec(p->mce_addr >> PAGE_SHIFT);
+       pfn = (p->mce_addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT;
+       if (!memory_failure(pfn, 0))
+               set_mce_nospec(pfn);
 }
 
 static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callback_head *))

diff --git a/drivers/edac/skx_common.c b/drivers/edac/skx_common.c
index f0f8e98f6efb289f0c415be7885f7473e65b8ca3..806986f03177737bcb15920a58caa2b5704f590a 100644 (file)
--- a/drivers/edac/skx_common.c
+++ b/drivers/edac/skx_common.c
@@ -657,7 +657,7 @@ int skx_mce_check_error(struct notifier_block *nb, unsigned long val,
 
        memset(&res, 0, sizeof(res));
        res.mce  = mce;
-       res.addr = mce->addr;
+       res.addr = mce->addr & MCI_ADDR_PHYSADDR;
 
        /* Try driver decoder first */
        if (!(driver_decode && driver_decode(&res))) {