Merge tag 'x86_cpu_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpuid updates from Borislav Petkov:

 - Make UMIP instruction detection more robust

 - Correct and cleanup AMD CPU topology detection; document the relevant
   CPUID leaves topology parsing precedence on AMD

 - Add support for running the kernel as guest on FreeBSD's Bhyve
   hypervisor

 - Cleanups and improvements

* tag 'x86_cpu_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/umip: Fix decoding of register forms of 0F 01 (SGDT and SIDT aliases)
  x86/umip: Check that the instruction opcode is at least two bytes
  Documentation/x86/topology: Detail CPUID leaves used for topology enumeration
  x86/cpu/topology: Define AMD64_CPUID_EXT_FEAT MSR
  x86/cpu/topology: Check for X86_FEATURE_XTOPOLOGY instead of passing has_xtopology
  x86/cpu/cacheinfo: Simplify cacheinfo_amd_init_llc_id() using _cpuid4_info
  x86/cpu: Rename and move CPU model entry for Diamond Rapids
  x86/cpu: Detect FreeBSD Bhyve hypervisor

10 files changed, 135 insertions, 47 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d8b793549ccb..679c7f980aa3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -883,6 +883,15 @@ config ACRN_GUEST
 	  IOT with small footprint and real-time features. More details can be
 	  found in https://projectacrn.org/.
 
+config BHYVE_GUEST
+	bool "Bhyve (BSD Hypervisor) Guest support"
+	depends on X86_64
+	help
+	  This option allows to run Linux to recognise when it is running as a
+	  guest in the Bhyve hypervisor, and to support more than 255 vCPUs when
+	  when doing so. More details about Bhyve can be found at https://bhyve.org
+	  and https://wiki.freebsd.org/bhyve/.
+
 config INTEL_TDX_GUEST
 	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
 	depends on X86_64 && CPU_SUP_INTEL
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index e41cbf2ec41d..9ad86a7d13f6 100644
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -30,6 +30,7 @@ enum x86_hypervisor_type {
 	X86_HYPER_KVM,
 	X86_HYPER_JAILHOUSE,
 	X86_HYPER_ACRN,
+	X86_HYPER_BHYVE,
 };
 
 #ifdef CONFIG_HYPERVISOR_GUEST
@@ -64,6 +65,7 @@ extern const struct hypervisor_x86 x86_hyper_xen_pv;
 extern const struct hypervisor_x86 x86_hyper_kvm;
 extern const struct hypervisor_x86 x86_hyper_jailhouse;
 extern const struct hypervisor_x86 x86_hyper_acrn;
+extern const struct hypervisor_x86 x86_hyper_bhyve;
 extern struct hypervisor_x86 x86_hyper_xen_hvm;
 
 extern bool nopv;
diff --git a/arch/x86/include/asm/intel-family.h b/arch/x86/include/asm/intel-family.h
index e345dbdf933e..f32a0eca2ae5 100644
--- a/arch/x86/include/asm/intel-family.h
+++ b/arch/x86/include/asm/intel-family.h
@@ -51,7 +51,7 @@
 #define INTEL_PENTIUM_MMX		IFM(5, 0x04) /* P55C */
 #define INTEL_QUARK_X1000		IFM(5, 0x09) /* Quark X1000 SoC */
 
-/* Family 6 */
+/* Family 6, 18, 19 */
 #define INTEL_PENTIUM_PRO		IFM(6, 0x01)
 #define INTEL_PENTIUM_II_KLAMATH	IFM(6, 0x03)
 #define INTEL_PENTIUM_III_DESCHUTES	IFM(6, 0x05)
@@ -126,6 +126,8 @@
 #define INTEL_GRANITERAPIDS_X		IFM(6, 0xAD) /* Redwood Cove */
 #define INTEL_GRANITERAPIDS_D		IFM(6, 0xAE)
 
+#define INTEL_DIAMONDRAPIDS_X		IFM(19, 0x01) /* Panther Cove */
+
 #define INTEL_BARTLETTLAKE		IFM(6, 0xD7) /* Raptor Cove */
 
 /* "Hybrid" Processors (P-Core/E-Core) */
@@ -203,9 +205,6 @@
 #define INTEL_P4_PRESCOTT_2M		IFM(15, 0x04)
 #define INTEL_P4_CEDARMILL		IFM(15, 0x06) /* Also Xeon Dempsey */
 
-/* Family 19 */
-#define INTEL_PANTHERCOVE_X		IFM(19, 0x01) /* Diamond Rapids */
-
 /*
  * Intel CPU core types
  *
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index f627196eb796..b60d3711a708 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -633,6 +633,11 @@
 #define MSR_AMD_PPIN			0xc00102f1
 #define MSR_AMD64_CPUID_FN_7		0xc0011002
 #define MSR_AMD64_CPUID_FN_1		0xc0011004
+
+#define MSR_AMD64_CPUID_EXT_FEAT	0xc0011005
+#define MSR_AMD64_CPUID_EXT_FEAT_TOPOEXT_BIT	54
+#define MSR_AMD64_CPUID_EXT_FEAT_TOPOEXT	BIT_ULL(MSR_AMD64_CPUID_EXT_FEAT_TOPOEXT_BIT)
+
 #define MSR_AMD64_LS_CFG		0xc0011020
 #define MSR_AMD64_DC_CFG		0xc0011022
 #define MSR_AMD64_TW_CFG		0xc0011023
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 1e26179ff18c..2f8a58ef690e 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_X86_SGX)			+= sgx/
 obj-$(CONFIG_X86_LOCAL_APIC)		+= perfctr-watchdog.o
 
 obj-$(CONFIG_HYPERVISOR_GUEST)		+= vmware.o hypervisor.o mshyperv.o
+obj-$(CONFIG_BHYVE_GUEST)		+= bhyve.o
 obj-$(CONFIG_ACRN_GUEST)		+= acrn.o
 
 obj-$(CONFIG_DEBUG_FS)			+= debugfs.o
diff --git a/arch/x86/kernel/cpu/bhyve.c b/arch/x86/kernel/cpu/bhyve.c
new file mode 100644
index 000000000000..f1a8ca3dd1ed
--- /dev/null
+++ b/arch/x86/kernel/cpu/bhyve.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FreeBSD Bhyve guest enlightenments
+ *
+ * Copyright © 2025 Amazon.com, Inc. or its affiliates.
+ *
+ * Author: David Woodhouse <dwmw2@infradead.org>
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+#include <asm/processor.h>
+#include <asm/hypervisor.h>
+
+static uint32_t bhyve_cpuid_base;
+static uint32_t bhyve_cpuid_max;
+
+#define BHYVE_SIGNATURE			"bhyve bhyve "
+
+#define CPUID_BHYVE_FEATURES		0x40000001
+
+/* Features advertised in CPUID_BHYVE_FEATURES %eax */
+
+/* MSI Extended Dest ID */
+#define CPUID_BHYVE_FEAT_EXT_DEST_ID	(1UL << 0)
+
+static uint32_t __init bhyve_detect(void)
+{
+	if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+                return 0;
+
+	bhyve_cpuid_base = cpuid_base_hypervisor(BHYVE_SIGNATURE, 0);
+	if (!bhyve_cpuid_base)
+		return 0;
+
+	bhyve_cpuid_max = cpuid_eax(bhyve_cpuid_base);
+	return bhyve_cpuid_max;
+}
+
+static uint32_t bhyve_features(void)
+{
+	unsigned int cpuid_leaf = bhyve_cpuid_base | CPUID_BHYVE_FEATURES;
+
+	if (bhyve_cpuid_max < cpuid_leaf)
+		return 0;
+
+	return cpuid_eax(cpuid_leaf);
+}
+
+static bool __init bhyve_ext_dest_id(void)
+{
+	return !!(bhyve_features() & CPUID_BHYVE_FEAT_EXT_DEST_ID);
+}
+
+static bool __init bhyve_x2apic_available(void)
+{
+	return true;
+}
+
+const struct hypervisor_x86 x86_hyper_bhyve __refconst = {
+	.name			= "Bhyve",
+	.detect			= bhyve_detect,
+	.init.init_platform	= x86_init_noop,
+	.init.x2apic_available	= bhyve_x2apic_available,
+	.init.msi_ext_dest_id	= bhyve_ext_dest_id,
+};
diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index adfa7e8bb865..51a95b07831f 100644
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -290,6 +290,22 @@ static int find_num_cache_leaves(struct cpuinfo_x86 *c)
 }
 
 /*
+ * The max shared threads number comes from CPUID(0x4) EAX[25-14] with input
+ * ECX as cache index. Then right shift apicid by the number's order to get
+ * cache id for this cache node.
+ */
+static unsigned int get_cache_id(u32 apicid, const struct _cpuid4_info *id4)
+{
+	unsigned long num_threads_sharing;
+	int index_msb;
+
+	num_threads_sharing = 1 + id4->eax.split.num_threads_sharing;
+	index_msb = get_count_order(num_threads_sharing);
+
+	return apicid >> index_msb;
+}
+
+/*
  * AMD/Hygon CPUs may have multiple LLCs if L3 caches exist.
  */
 
@@ -312,18 +328,11 @@ void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, u16 die_id)
 		 * Newer families: LLC ID is calculated from the number
 		 * of threads sharing the L3 cache.
 		 */
-		u32 eax, ebx, ecx, edx, num_sharing_cache = 0;
 		u32 llc_index = find_num_cache_leaves(c) - 1;
+		struct _cpuid4_info id4 = {};
 
-		cpuid_count(0x8000001d, llc_index, &eax, &ebx, &ecx, &edx);
-		if (eax)
-			num_sharing_cache = ((eax >> 14) & 0xfff) + 1;
-
-		if (num_sharing_cache) {
-			int index_msb = get_count_order(num_sharing_cache);
-
-			c->topo.llc_id = c->topo.apicid >> index_msb;
-		}
+		if (!amd_fill_cpuid4_info(llc_index, &id4))
+			c->topo.llc_id = get_cache_id(c->topo.apicid, &id4);
 	}
 }
 
@@ -598,27 +607,12 @@ int init_cache_level(unsigned int cpu)
 	return 0;
 }
 
-/*
- * The max shared threads number comes from CPUID(0x4) EAX[25-14] with input
- * ECX as cache index. Then right shift apicid by the number's order to get
- * cache id for this cache node.
- */
-static void get_cache_id(int cpu, struct _cpuid4_info *id4)
-{
-	struct cpuinfo_x86 *c = &cpu_data(cpu);
-	unsigned long num_threads_sharing;
-	int index_msb;
-
-	num_threads_sharing = 1 + id4->eax.split.num_threads_sharing;
-	index_msb = get_count_order(num_threads_sharing);
-	id4->id = c->topo.apicid >> index_msb;
-}
-
 int populate_cache_leaves(unsigned int cpu)
 {
 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 	struct cacheinfo *ci = this_cpu_ci->info_list;
 	u8 cpu_vendor = boot_cpu_data.x86_vendor;
+	u32 apicid = cpu_data(cpu).topo.apicid;
 	struct amd_northbridge *nb = NULL;
 	struct _cpuid4_info id4 = {};
 	int idx, ret;
@@ -628,7 +622,7 @@ int populate_cache_leaves(unsigned int cpu)
 		if (ret)
 			return ret;
 
-		get_cache_id(cpu, &id4);
+		id4.id = get_cache_id(apicid, &id4);
 
 		if (cpu_vendor == X86_VENDOR_AMD || cpu_vendor == X86_VENDOR_HYGON)
 			nb = amd_init_l3_cache(idx);
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 553bfbfc3a1b..f3e9219845e8 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -45,6 +45,9 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
 #ifdef CONFIG_ACRN_GUEST
 	&x86_hyper_acrn,
 #endif
+#ifdef CONFIG_BHYVE_GUEST
+	&x86_hyper_bhyve,
+#endif
 };
 
 enum x86_hypervisor_type x86_hyper_type;
diff --git a/arch/x86/kernel/cpu/topology_amd.c b/arch/x86/kernel/cpu/topology_amd.c
index c79ebbb639cb..6ac097e13106 100644
--- a/arch/x86/kernel/cpu/topology_amd.c
+++ b/arch/x86/kernel/cpu/topology_amd.c
@@ -59,7 +59,7 @@ static void store_node(struct topo_scan *tscan, u16 nr_nodes, u16 node_id)
 	tscan->amd_node_id = node_id;
 }
 
-static bool parse_8000_001e(struct topo_scan *tscan, bool has_topoext)
+static bool parse_8000_001e(struct topo_scan *tscan)
 {
 	struct {
 		// eax
@@ -85,7 +85,7 @@ static bool parse_8000_001e(struct topo_scan *tscan, bool has_topoext)
 	 * If leaf 0xb/0x26 is available, then the APIC ID and the domain
 	 * shifts are set already.
 	 */
-	if (!has_topoext) {
+	if (!cpu_feature_enabled(X86_FEATURE_XTOPOLOGY)) {
 		tscan->c->topo.initial_apicid = leaf.ext_apic_id;
 
 		/*
@@ -163,11 +163,12 @@ static void topoext_fixup(struct topo_scan *tscan)
 	    c->x86 != 0x15 || c->x86_model < 0x10 || c->x86_model > 0x6f)
 		return;
 
-	if (msr_set_bit(0xc0011005, 54) <= 0)
+	if (msr_set_bit(MSR_AMD64_CPUID_EXT_FEAT,
+			MSR_AMD64_CPUID_EXT_FEAT_TOPOEXT_BIT) <= 0)
 		return;
 
-	rdmsrq(0xc0011005, msrval);
-	if (msrval & BIT_64(54)) {
+	rdmsrq(MSR_AMD64_CPUID_EXT_FEAT, msrval);
+	if (msrval & MSR_AMD64_CPUID_EXT_FEAT_TOPOEXT) {
 		set_cpu_cap(c, X86_FEATURE_TOPOEXT);
 		pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
 	}
@@ -175,30 +176,27 @@ static void topoext_fixup(struct topo_scan *tscan)
 
 static void parse_topology_amd(struct topo_scan *tscan)
 {
+	if (cpu_feature_enabled(X86_FEATURE_AMD_HTR_CORES))
+		tscan->c->topo.cpu_type = cpuid_ebx(0x80000026);
+
 	/*
 	 * Try to get SMT, CORE, TILE, and DIE shifts from extended
 	 * CPUID leaf 0x8000_0026 on supported processors first. If
 	 * extended CPUID leaf 0x8000_0026 is not supported, try to
 	 * get SMT and CORE shift from leaf 0xb. If either leaf is
 	 * available, cpu_parse_topology_ext() will return true.
-	 */
-	bool has_xtopology = cpu_parse_topology_ext(tscan);
-
-	if (cpu_feature_enabled(X86_FEATURE_AMD_HTR_CORES))
-		tscan->c->topo.cpu_type = cpuid_ebx(0x80000026);
-
-	/*
+	 *
 	 * If XTOPOLOGY leaves (0x26/0xb) are not available, try to
 	 * get the CORE shift from leaf 0x8000_0008 first.
 	 */
-	if (!has_xtopology && !parse_8000_0008(tscan))
+	if (!cpu_parse_topology_ext(tscan) && !parse_8000_0008(tscan))
 		return;
 
 	/*
 	 * Prefer leaf 0x8000001e if available to get the SMT shift and
 	 * the initial APIC ID if XTOPOLOGY leaves are not available.
 	 */
-	if (parse_8000_001e(tscan, has_xtopology))
+	if (parse_8000_001e(tscan))
 		return;
 
 	/* Try the NODEID MSR */
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index 5a4b21389b1d..d432f3824f0c 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -156,15 +156,26 @@ static int identify_insn(struct insn *insn)
 	if (!insn->modrm.nbytes)
 		return -EINVAL;
 
-	/* All the instructions of interest start with 0x0f. */
-	if (insn->opcode.bytes[0] != 0xf)
+	/* The instructions of interest have 2-byte opcodes: 0F 00 or 0F 01. */
+	if (insn->opcode.nbytes < 2 || insn->opcode.bytes[0] != 0xf)
 		return -EINVAL;
 
 	if (insn->opcode.bytes[1] == 0x1) {
 		switch (X86_MODRM_REG(insn->modrm.value)) {
 		case 0:
+			/* The reg form of 0F 01 /0 encodes VMX instructions. */
+			if (X86_MODRM_MOD(insn->modrm.value) == 3)
+				return -EINVAL;
+
 			return UMIP_INST_SGDT;
 		case 1:
+			/*
+			 * The reg form of 0F 01 /1 encodes MONITOR/MWAIT,
+			 * STAC/CLAC, and ENCLS.
+			 */
+			if (X86_MODRM_MOD(insn->modrm.value) == 3)
+				return -EINVAL;
+
 			return UMIP_INST_SIDT;
 		case 4:
 			return UMIP_INST_SMSW;