Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 515 insertions, 0 deletions

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
new file mode 100644
index 000000000..d63ad8f99
--- /dev/null
+++ b/arch/x86/boot/compressed/sev.c
@@ -0,0 +1,515 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Encrypted Register State Support
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+/*
+ * misc.h needs to be first because it knows how to include the other kernel
+ * headers in the pre-decompression code in a way that does not break
+ * compilation.
+ */
+#include "misc.h"
+
+#include <asm/pgtable_types.h>
+#include <asm/sev.h>
+#include <asm/trapnr.h>
+#include <asm/trap_pf.h>
+#include <asm/msr-index.h>
+#include <asm/fpu/xcr.h>
+#include <asm/ptrace.h>
+#include <asm/svm.h>
+#include <asm/cpuid.h>
+
+#include "error.h"
+#include "../msr.h"
+
+struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);
+struct ghcb *boot_ghcb;
+
+/*
+ * Copy a version of this function here - insn-eval.c can't be used in
+ * pre-decompression code.
+ */
+static bool insn_has_rep_prefix(struct insn *insn)
+{
+	insn_byte_t p;
+	int i;
+
+	insn_get_prefixes(insn);
+
+	for_each_insn_prefix(insn, i, p) {
+		if (p == 0xf2 || p == 0xf3)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and
+ * doesn't use segments.
+ */
+static unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx)
+{
+	return 0UL;
+}
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+	struct msr m;
+
+	boot_rdmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+
+	return m.q;
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+	struct msr m;
+
+	m.q = val;
+	boot_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+}
+
+static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+	char buffer[MAX_INSN_SIZE];
+	int ret;
+
+	memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
+
+	ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64);
+	if (ret < 0)
+		return ES_DECODE_FAILED;
+
+	return ES_OK;
+}
+
+static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
+				   void *dst, char *buf, size_t size)
+{
+	memcpy(dst, buf, size);
+
+	return ES_OK;
+}
+
+static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
+				  void *src, char *buf, size_t size)
+{
+	memcpy(buf, src, size);
+
+	return ES_OK;
+}
+
+#undef __init
+#undef __pa
+#define __init
+#define __pa(x)	((unsigned long)(x))
+
+#define __BOOT_COMPRESSED
+
+/* Basic instruction decoding support needed */
+#include "../../lib/inat.c"
+#include "../../lib/insn.c"
+
+/* Include code for early handlers */
+#include "../../kernel/sev-shared.c"
+
+static inline bool sev_snp_enabled(void)
+{
+	return sev_status & MSR_AMD64_SEV_SNP_ENABLED;
+}
+
+static void __page_state_change(unsigned long paddr, enum psc_op op)
+{
+	u64 val;
+
+	if (!sev_snp_enabled())
+		return;
+
+	/*
+	 * If private -> shared then invalidate the page before requesting the
+	 * state change in the RMP table.
+	 */
+	if (op == SNP_PAGE_STATE_SHARED && pvalidate(paddr, RMP_PG_SIZE_4K, 0))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+
+	/* Issue VMGEXIT to change the page state in RMP table. */
+	sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, op));
+	VMGEXIT();
+
+	/* Read the response of the VMGEXIT. */
+	val = sev_es_rd_ghcb_msr();
+	if ((GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) || GHCB_MSR_PSC_RESP_VAL(val))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
+
+	/*
+	 * Now that page state is changed in the RMP table, validate it so that it is
+	 * consistent with the RMP entry.
+	 */
+	if (op == SNP_PAGE_STATE_PRIVATE && pvalidate(paddr, RMP_PG_SIZE_4K, 1))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+}
+
+void snp_set_page_private(unsigned long paddr)
+{
+	__page_state_change(paddr, SNP_PAGE_STATE_PRIVATE);
+}
+
+void snp_set_page_shared(unsigned long paddr)
+{
+	__page_state_change(paddr, SNP_PAGE_STATE_SHARED);
+}
+
+static bool early_setup_ghcb(void)
+{
+	if (set_page_decrypted((unsigned long)&boot_ghcb_page))
+		return false;
+
+	/* Page is now mapped decrypted, clear it */
+	memset(&boot_ghcb_page, 0, sizeof(boot_ghcb_page));
+
+	boot_ghcb = &boot_ghcb_page;
+
+	/* Initialize lookup tables for the instruction decoder */
+	inat_init_tables();
+
+	/* SNP guest requires the GHCB GPA must be registered */
+	if (sev_snp_enabled())
+		snp_register_ghcb_early(__pa(&boot_ghcb_page));
+
+	return true;
+}
+
+void sev_es_shutdown_ghcb(void)
+{
+	if (!boot_ghcb)
+		return;
+
+	if (!sev_es_check_cpu_features())
+		error("SEV-ES CPU Features missing.");
+
+	/*
+	 * GHCB Page must be flushed from the cache and mapped encrypted again.
+	 * Otherwise the running kernel will see strange cache effects when
+	 * trying to use that page.
+	 */
+	if (set_page_encrypted((unsigned long)&boot_ghcb_page))
+		error("Can't map GHCB page encrypted");
+
+	/*
+	 * GHCB page is mapped encrypted again and flushed from the cache.
+	 * Mark it non-present now to catch bugs when #VC exceptions trigger
+	 * after this point.
+	 */
+	if (set_page_non_present((unsigned long)&boot_ghcb_page))
+		error("Can't unmap GHCB page");
+}
+
+static void __noreturn sev_es_ghcb_terminate(struct ghcb *ghcb, unsigned int set,
+					     unsigned int reason, u64 exit_info_2)
+{
+	u64 exit_info_1 = SVM_VMGEXIT_TERM_REASON(set, reason);
+
+	vc_ghcb_invalidate(ghcb);
+	ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_TERM_REQUEST);
+	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+	sev_es_wr_ghcb_msr(__pa(ghcb));
+	VMGEXIT();
+
+	while (true)
+		asm volatile("hlt\n" : : : "memory");
+}
+
+bool sev_es_check_ghcb_fault(unsigned long address)
+{
+	/* Check whether the fault was on the GHCB page */
+	return ((address & PAGE_MASK) == (unsigned long)&boot_ghcb_page);
+}
+
+void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
+{
+	struct es_em_ctxt ctxt;
+	enum es_result result;
+
+	if (!boot_ghcb && !early_setup_ghcb())
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+
+	vc_ghcb_invalidate(boot_ghcb);
+	result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+	if (result != ES_OK)
+		goto finish;
+
+	switch (exit_code) {
+	case SVM_EXIT_RDTSC:
+	case SVM_EXIT_RDTSCP:
+		result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code);
+		break;
+	case SVM_EXIT_IOIO:
+		result = vc_handle_ioio(boot_ghcb, &ctxt);
+		break;
+	case SVM_EXIT_CPUID:
+		result = vc_handle_cpuid(boot_ghcb, &ctxt);
+		break;
+	default:
+		result = ES_UNSUPPORTED;
+		break;
+	}
+
+finish:
+	if (result == ES_OK)
+		vc_finish_insn(&ctxt);
+	else if (result != ES_RETRY)
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+}
+
+static void enforce_vmpl0(void)
+{
+	u64 attrs;
+	int err;
+
+	/*
+	 * RMPADJUST modifies RMP permissions of a lesser-privileged (numerically
+	 * higher) privilege level. Here, clear the VMPL1 permission mask of the
+	 * GHCB page. If the guest is not running at VMPL0, this will fail.
+	 *
+	 * If the guest is running at VMPL0, it will succeed. Even if that operation
+	 * modifies permission bits, it is still ok to do so currently because Linux
+	 * SNP guests are supported only on VMPL0 so VMPL1 or higher permission masks
+	 * changing is a don't-care.
+	 */
+	attrs = 1;
+	if (rmpadjust((unsigned long)&boot_ghcb_page, RMP_PG_SIZE_4K, attrs))
+		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0);
+}
+
+/*
+ * SNP_FEATURES_IMPL_REQ is the mask of SNP features that will need
+ * guest side implementation for proper functioning of the guest. If any
+ * of these features are enabled in the hypervisor but are lacking guest
+ * side implementation, the behavior of the guest will be undefined. The
+ * guest could fail in non-obvious way making it difficult to debug.
+ *
+ * As the behavior of reserved feature bits is unknown to be on the
+ * safe side add them to the required features mask.
+ */
+#define SNP_FEATURES_IMPL_REQ	(MSR_AMD64_SNP_VTOM |			\
+				 MSR_AMD64_SNP_REFLECT_VC |		\
+				 MSR_AMD64_SNP_RESTRICTED_INJ |		\
+				 MSR_AMD64_SNP_ALT_INJ |		\
+				 MSR_AMD64_SNP_DEBUG_SWAP |		\
+				 MSR_AMD64_SNP_VMPL_SSS |		\
+				 MSR_AMD64_SNP_SECURE_TSC |		\
+				 MSR_AMD64_SNP_VMGEXIT_PARAM |		\
+				 MSR_AMD64_SNP_VMSA_REG_PROTECTION |	\
+				 MSR_AMD64_SNP_RESERVED_BIT13 |		\
+				 MSR_AMD64_SNP_RESERVED_BIT15 |		\
+				 MSR_AMD64_SNP_RESERVED_MASK)
+
+/*
+ * SNP_FEATURES_PRESENT is the mask of SNP features that are implemented
+ * by the guest kernel. As and when a new feature is implemented in the
+ * guest kernel, a corresponding bit should be added to the mask.
+ */
+#define SNP_FEATURES_PRESENT (0)
+
+void snp_check_features(void)
+{
+	u64 unsupported;
+
+	if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+		return;
+
+	/*
+	 * Terminate the boot if hypervisor has enabled any feature lacking
+	 * guest side implementation. Pass on the unsupported features mask through
+	 * EXIT_INFO_2 of the GHCB protocol so that those features can be reported
+	 * as part of the guest boot failure.
+	 */
+	unsupported = sev_status & SNP_FEATURES_IMPL_REQ & ~SNP_FEATURES_PRESENT;
+	if (unsupported) {
+		if (ghcb_version < 2 || (!boot_ghcb && !early_setup_ghcb()))
+			sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+		sev_es_ghcb_terminate(boot_ghcb, SEV_TERM_SET_GEN,
+				      GHCB_SNP_UNSUPPORTED, unsupported);
+	}
+}
+
+void sev_enable(struct boot_params *bp)
+{
+	unsigned int eax, ebx, ecx, edx;
+	struct msr m;
+	bool snp;
+
+	/*
+	 * bp->cc_blob_address should only be set by boot/compressed kernel.
+	 * Initialize it to 0 to ensure that uninitialized values from
+	 * buggy bootloaders aren't propagated.
+	 */
+	if (bp)
+		bp->cc_blob_address = 0;
+
+	/*
+	 * Setup/preliminary detection of SNP. This will be sanity-checked
+	 * against CPUID/MSR values later.
+	 */
+	snp = snp_init(bp);
+
+	/* Check for the SME/SEV support leaf */
+	eax = 0x80000000;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (eax < 0x8000001f)
+		return;
+
+	/*
+	 * Check for the SME/SEV feature:
+	 *   CPUID Fn8000_001F[EAX]
+	 *   - Bit 0 - Secure Memory Encryption support
+	 *   - Bit 1 - Secure Encrypted Virtualization support
+	 *   CPUID Fn8000_001F[EBX]
+	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+	 */
+	eax = 0x8000001f;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	/* Check whether SEV is supported */
+	if (!(eax & BIT(1))) {
+		if (snp)
+			error("SEV-SNP support indicated by CC blob, but not CPUID.");
+		return;
+	}
+
+	/* Set the SME mask if this is an SEV guest. */
+	boot_rdmsr(MSR_AMD64_SEV, &m);
+	sev_status = m.q;
+	if (!(sev_status & MSR_AMD64_SEV_ENABLED))
+		return;
+
+	/* Negotiate the GHCB protocol version. */
+	if (sev_status & MSR_AMD64_SEV_ES_ENABLED) {
+		if (!sev_es_negotiate_protocol())
+			sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_PROT_UNSUPPORTED);
+	}
+
+	/*
+	 * SNP is supported in v2 of the GHCB spec which mandates support for HV
+	 * features.
+	 */
+	if (sev_status & MSR_AMD64_SEV_SNP_ENABLED) {
+		if (!(get_hv_features() & GHCB_HV_FT_SNP))
+			sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+		enforce_vmpl0();
+	}
+
+	if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+		error("SEV-SNP supported indicated by CC blob, but not SEV status MSR.");
+
+	sme_me_mask = BIT_ULL(ebx & 0x3f);
+}
+
+/* Search for Confidential Computing blob in the EFI config table. */
+static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp)
+{
+	unsigned long cfg_table_pa;
+	unsigned int cfg_table_len;
+	int ret;
+
+	ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len);
+	if (ret)
+		return NULL;
+
+	return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa,
+								cfg_table_len,
+								EFI_CC_BLOB_GUID);
+}
+
+/*
+ * Initial set up of SNP relies on information provided by the
+ * Confidential Computing blob, which can be passed to the boot kernel
+ * by firmware/bootloader in the following ways:
+ *
+ * - via an entry in the EFI config table
+ * - via a setup_data structure, as defined by the Linux Boot Protocol
+ *
+ * Scan for the blob in that order.
+ */
+static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	cc_info = find_cc_blob_efi(bp);
+	if (cc_info)
+		goto found_cc_info;
+
+	cc_info = find_cc_blob_setup_data(bp);
+	if (!cc_info)
+		return NULL;
+
+found_cc_info:
+	if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+	return cc_info;
+}
+
+/*
+ * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks
+ * will verify the SNP CPUID/MSR bits.
+ */
+bool snp_init(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	if (!bp)
+		return false;
+
+	cc_info = find_cc_blob(bp);
+	if (!cc_info)
+		return false;
+
+	/*
+	 * If a SNP-specific Confidential Computing blob is present, then
+	 * firmware/bootloader have indicated SNP support. Verifying this
+	 * involves CPUID checks which will be more reliable if the SNP
+	 * CPUID table is used. See comments over snp_setup_cpuid_table() for
+	 * more details.
+	 */
+	setup_cpuid_table(cc_info);
+
+	/*
+	 * Pass run-time kernel a pointer to CC info via boot_params so EFI
+	 * config table doesn't need to be searched again during early startup
+	 * phase.
+	 */
+	bp->cc_blob_address = (u32)(unsigned long)cc_info;
+
+	return true;
+}
+
+void sev_prep_identity_maps(unsigned long top_level_pgt)
+{
+	/*
+	 * The Confidential Computing blob is used very early in uncompressed
+	 * kernel to find the in-memory CPUID table to handle CPUID
+	 * instructions. Make sure an identity-mapping exists so it can be
+	 * accessed after switchover.
+	 */
+	if (sev_snp_enabled()) {
+		unsigned long cc_info_pa = boot_params->cc_blob_address;
+		struct cc_blob_sev_info *cc_info;
+
+		kernel_add_identity_map(cc_info_pa, cc_info_pa + sizeof(*cc_info));
+
+		cc_info = (struct cc_blob_sev_info *)cc_info_pa;
+		kernel_add_identity_map(cc_info->cpuid_phys, cc_info->cpuid_phys + cc_info->cpuid_len);
+	}
+
+	sev_verify_cbit(top_level_pgt);
+}