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-rw-r--r--arch/x86/kernel/cpu/bugs.c46
-rw-r--r--arch/x86/kernel/cpu/common.c1
-rw-r--r--arch/x86/kernel/cpu/intel.c3
-rw-r--r--arch/x86/kernel/cpu/microcode/amd.c24
-rw-r--r--arch/x86/kernel/cpu/microcode/intel.c17
5 files changed, 73 insertions, 18 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 4c2313d0b9ca..40bdaea97fe7 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -668,6 +668,45 @@ EXPORT_SYMBOL_GPL(l1tf_mitigation);
enum vmx_l1d_flush_state l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO;
EXPORT_SYMBOL_GPL(l1tf_vmx_mitigation);
+/*
+ * These CPUs all support 44bits physical address space internally in the
+ * cache but CPUID can report a smaller number of physical address bits.
+ *
+ * The L1TF mitigation uses the top most address bit for the inversion of
+ * non present PTEs. When the installed memory reaches into the top most
+ * address bit due to memory holes, which has been observed on machines
+ * which report 36bits physical address bits and have 32G RAM installed,
+ * then the mitigation range check in l1tf_select_mitigation() triggers.
+ * This is a false positive because the mitigation is still possible due to
+ * the fact that the cache uses 44bit internally. Use the cache bits
+ * instead of the reported physical bits and adjust them on the affected
+ * machines to 44bit if the reported bits are less than 44.
+ */
+static void override_cache_bits(struct cpuinfo_x86 *c)
+{
+ if (c->x86 != 6)
+ return;
+
+ switch (c->x86_model) {
+ case INTEL_FAM6_NEHALEM:
+ case INTEL_FAM6_WESTMERE:
+ case INTEL_FAM6_SANDYBRIDGE:
+ case INTEL_FAM6_IVYBRIDGE:
+ case INTEL_FAM6_HASWELL_CORE:
+ case INTEL_FAM6_HASWELL_ULT:
+ case INTEL_FAM6_HASWELL_GT3E:
+ case INTEL_FAM6_BROADWELL_CORE:
+ case INTEL_FAM6_BROADWELL_GT3E:
+ case INTEL_FAM6_SKYLAKE_MOBILE:
+ case INTEL_FAM6_SKYLAKE_DESKTOP:
+ case INTEL_FAM6_KABYLAKE_MOBILE:
+ case INTEL_FAM6_KABYLAKE_DESKTOP:
+ if (c->x86_cache_bits < 44)
+ c->x86_cache_bits = 44;
+ break;
+ }
+}
+
static void __init l1tf_select_mitigation(void)
{
u64 half_pa;
@@ -675,6 +714,8 @@ static void __init l1tf_select_mitigation(void)
if (!boot_cpu_has_bug(X86_BUG_L1TF))
return;
+ override_cache_bits(&boot_cpu_data);
+
switch (l1tf_mitigation) {
case L1TF_MITIGATION_OFF:
case L1TF_MITIGATION_FLUSH_NOWARN:
@@ -694,11 +735,6 @@ static void __init l1tf_select_mitigation(void)
return;
#endif
- /*
- * This is extremely unlikely to happen because almost all
- * systems have far more MAX_PA/2 than RAM can be fit into
- * DIMM slots.
- */
half_pa = (u64)l1tf_pfn_limit() << PAGE_SHIFT;
if (e820__mapped_any(half_pa, ULLONG_MAX - half_pa, E820_TYPE_RAM)) {
pr_warn("System has more than MAX_PA/2 memory. L1TF mitigation not effective.\n");
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 84dee5ab745a..44c4ef3d989b 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -919,6 +919,7 @@ void get_cpu_address_sizes(struct cpuinfo_x86 *c)
else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
c->x86_phys_bits = 36;
#endif
+ c->x86_cache_bits = c->x86_phys_bits;
}
static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 401e8c133108..fc3c07fe7df5 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -150,6 +150,9 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_HYPERVISOR))
return false;
+ if (c->x86 != 6)
+ return false;
+
for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
if (c->x86_model == spectre_bad_microcodes[i].model &&
c->x86_stepping == spectre_bad_microcodes[i].stepping)
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 0624957aa068..07b5fc00b188 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -504,6 +504,7 @@ static enum ucode_state apply_microcode_amd(int cpu)
struct microcode_amd *mc_amd;
struct ucode_cpu_info *uci;
struct ucode_patch *p;
+ enum ucode_state ret;
u32 rev, dummy;
BUG_ON(raw_smp_processor_id() != cpu);
@@ -521,9 +522,8 @@ static enum ucode_state apply_microcode_amd(int cpu)
/* need to apply patch? */
if (rev >= mc_amd->hdr.patch_id) {
- c->microcode = rev;
- uci->cpu_sig.rev = rev;
- return UCODE_OK;
+ ret = UCODE_OK;
+ goto out;
}
if (__apply_microcode_amd(mc_amd)) {
@@ -531,13 +531,21 @@ static enum ucode_state apply_microcode_amd(int cpu)
cpu, mc_amd->hdr.patch_id);
return UCODE_ERROR;
}
- pr_info("CPU%d: new patch_level=0x%08x\n", cpu,
- mc_amd->hdr.patch_id);
- uci->cpu_sig.rev = mc_amd->hdr.patch_id;
- c->microcode = mc_amd->hdr.patch_id;
+ rev = mc_amd->hdr.patch_id;
+ ret = UCODE_UPDATED;
+
+ pr_info("CPU%d: new patch_level=0x%08x\n", cpu, rev);
- return UCODE_UPDATED;
+out:
+ uci->cpu_sig.rev = rev;
+ c->microcode = rev;
+
+ /* Update boot_cpu_data's revision too, if we're on the BSP: */
+ if (c->cpu_index == boot_cpu_data.cpu_index)
+ boot_cpu_data.microcode = rev;
+
+ return ret;
}
static int install_equiv_cpu_table(const u8 *buf)
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 97ccf4c3b45b..16936a24795c 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -795,6 +795,7 @@ static enum ucode_state apply_microcode_intel(int cpu)
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
struct cpuinfo_x86 *c = &cpu_data(cpu);
struct microcode_intel *mc;
+ enum ucode_state ret;
static int prev_rev;
u32 rev;
@@ -817,9 +818,8 @@ static enum ucode_state apply_microcode_intel(int cpu)
*/
rev = intel_get_microcode_revision();
if (rev >= mc->hdr.rev) {
- uci->cpu_sig.rev = rev;
- c->microcode = rev;
- return UCODE_OK;
+ ret = UCODE_OK;
+ goto out;
}
/*
@@ -848,10 +848,17 @@ static enum ucode_state apply_microcode_intel(int cpu)
prev_rev = rev;
}
+ ret = UCODE_UPDATED;
+
+out:
uci->cpu_sig.rev = rev;
- c->microcode = rev;
+ c->microcode = rev;
+
+ /* Update boot_cpu_data's revision too, if we're on the BSP: */
+ if (c->cpu_index == boot_cpu_data.cpu_index)
+ boot_cpu_data.microcode = rev;
- return UCODE_UPDATED;
+ return ret;
}
static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
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