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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/x86/mm/mem_encrypt_identity.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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(). ...
Diffstat (limited to 'arch/x86/mm/mem_encrypt_identity.c')
-rw-r--r--arch/x86/mm/mem_encrypt_identity.c617
1 files changed, 617 insertions, 0 deletions
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
new file mode 100644
index 000000000..88cccd650
--- /dev/null
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -0,0 +1,617 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2016 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+/*
+ * Since we're dealing with identity mappings, physical and virtual
+ * addresses are the same, so override these defines which are ultimately
+ * used by the headers in misc.h.
+ */
+#define __pa(x) ((unsigned long)(x))
+#define __va(x) ((void *)((unsigned long)(x)))
+
+/*
+ * Special hack: we have to be careful, because no indirections are
+ * allowed here, and paravirt_ops is a kind of one. As it will only run in
+ * baremetal anyway, we just keep it from happening. (This list needs to
+ * be extended when new paravirt and debugging variants are added.)
+ */
+#undef CONFIG_PARAVIRT
+#undef CONFIG_PARAVIRT_XXL
+#undef CONFIG_PARAVIRT_SPINLOCKS
+
+/*
+ * This code runs before CPU feature bits are set. By default, the
+ * pgtable_l5_enabled() function uses bit X86_FEATURE_LA57 to determine if
+ * 5-level paging is active, so that won't work here. USE_EARLY_PGTABLE_L5
+ * is provided to handle this situation and, instead, use a variable that
+ * has been set by the early boot code.
+ */
+#define USE_EARLY_PGTABLE_L5
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/mem_encrypt.h>
+#include <linux/cc_platform.h>
+
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cmdline.h>
+#include <asm/coco.h>
+#include <asm/sev.h>
+
+#include "mm_internal.h"
+
+#define PGD_FLAGS _KERNPG_TABLE_NOENC
+#define P4D_FLAGS _KERNPG_TABLE_NOENC
+#define PUD_FLAGS _KERNPG_TABLE_NOENC
+#define PMD_FLAGS _KERNPG_TABLE_NOENC
+
+#define PMD_FLAGS_LARGE (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL)
+
+#define PMD_FLAGS_DEC PMD_FLAGS_LARGE
+#define PMD_FLAGS_DEC_WP ((PMD_FLAGS_DEC & ~_PAGE_LARGE_CACHE_MASK) | \
+ (_PAGE_PAT_LARGE | _PAGE_PWT))
+
+#define PMD_FLAGS_ENC (PMD_FLAGS_LARGE | _PAGE_ENC)
+
+#define PTE_FLAGS (__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL)
+
+#define PTE_FLAGS_DEC PTE_FLAGS
+#define PTE_FLAGS_DEC_WP ((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \
+ (_PAGE_PAT | _PAGE_PWT))
+
+#define PTE_FLAGS_ENC (PTE_FLAGS | _PAGE_ENC)
+
+struct sme_populate_pgd_data {
+ void *pgtable_area;
+ pgd_t *pgd;
+
+ pmdval_t pmd_flags;
+ pteval_t pte_flags;
+ unsigned long paddr;
+
+ unsigned long vaddr;
+ unsigned long vaddr_end;
+};
+
+/*
+ * This work area lives in the .init.scratch section, which lives outside of
+ * the kernel proper. It is sized to hold the intermediate copy buffer and
+ * more than enough pagetable pages.
+ *
+ * By using this section, the kernel can be encrypted in place and it
+ * avoids any possibility of boot parameters or initramfs images being
+ * placed such that the in-place encryption logic overwrites them. This
+ * section is 2MB aligned to allow for simple pagetable setup using only
+ * PMD entries (see vmlinux.lds.S).
+ */
+static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch");
+
+static char sme_cmdline_arg[] __initdata = "mem_encrypt";
+static char sme_cmdline_on[] __initdata = "on";
+static char sme_cmdline_off[] __initdata = "off";
+
+static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd)
+{
+ unsigned long pgd_start, pgd_end, pgd_size;
+ pgd_t *pgd_p;
+
+ pgd_start = ppd->vaddr & PGDIR_MASK;
+ pgd_end = ppd->vaddr_end & PGDIR_MASK;
+
+ pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t);
+
+ pgd_p = ppd->pgd + pgd_index(ppd->vaddr);
+
+ memset(pgd_p, 0, pgd_size);
+}
+
+static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd)
+{
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = ppd->pgd + pgd_index(ppd->vaddr);
+ if (pgd_none(*pgd)) {
+ p4d = ppd->pgtable_area;
+ memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D);
+ ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D;
+ set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d)));
+ }
+
+ p4d = p4d_offset(pgd, ppd->vaddr);
+ if (p4d_none(*p4d)) {
+ pud = ppd->pgtable_area;
+ memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD);
+ ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD;
+ set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud)));
+ }
+
+ pud = pud_offset(p4d, ppd->vaddr);
+ if (pud_none(*pud)) {
+ pmd = ppd->pgtable_area;
+ memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD);
+ ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD;
+ set_pud(pud, __pud(PUD_FLAGS | __pa(pmd)));
+ }
+
+ if (pud_large(*pud))
+ return NULL;
+
+ return pud;
+}
+
+static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
+{
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pud = sme_prepare_pgd(ppd);
+ if (!pud)
+ return;
+
+ pmd = pmd_offset(pud, ppd->vaddr);
+ if (pmd_large(*pmd))
+ return;
+
+ set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
+}
+
+static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
+{
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pud = sme_prepare_pgd(ppd);
+ if (!pud)
+ return;
+
+ pmd = pmd_offset(pud, ppd->vaddr);
+ if (pmd_none(*pmd)) {
+ pte = ppd->pgtable_area;
+ memset(pte, 0, sizeof(*pte) * PTRS_PER_PTE);
+ ppd->pgtable_area += sizeof(*pte) * PTRS_PER_PTE;
+ set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte)));
+ }
+
+ if (pmd_large(*pmd))
+ return;
+
+ pte = pte_offset_map(pmd, ppd->vaddr);
+ if (pte_none(*pte))
+ set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
+}
+
+static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
+{
+ while (ppd->vaddr < ppd->vaddr_end) {
+ sme_populate_pgd_large(ppd);
+
+ ppd->vaddr += PMD_SIZE;
+ ppd->paddr += PMD_SIZE;
+ }
+}
+
+static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd)
+{
+ while (ppd->vaddr < ppd->vaddr_end) {
+ sme_populate_pgd(ppd);
+
+ ppd->vaddr += PAGE_SIZE;
+ ppd->paddr += PAGE_SIZE;
+ }
+}
+
+static void __init __sme_map_range(struct sme_populate_pgd_data *ppd,
+ pmdval_t pmd_flags, pteval_t pte_flags)
+{
+ unsigned long vaddr_end;
+
+ ppd->pmd_flags = pmd_flags;
+ ppd->pte_flags = pte_flags;
+
+ /* Save original end value since we modify the struct value */
+ vaddr_end = ppd->vaddr_end;
+
+ /* If start is not 2MB aligned, create PTE entries */
+ ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_SIZE);
+ __sme_map_range_pte(ppd);
+
+ /* Create PMD entries */
+ ppd->vaddr_end = vaddr_end & PMD_MASK;
+ __sme_map_range_pmd(ppd);
+
+ /* If end is not 2MB aligned, create PTE entries */
+ ppd->vaddr_end = vaddr_end;
+ __sme_map_range_pte(ppd);
+}
+
+static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd)
+{
+ __sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC);
+}
+
+static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd)
+{
+ __sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC);
+}
+
+static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd)
+{
+ __sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP);
+}
+
+static unsigned long __init sme_pgtable_calc(unsigned long len)
+{
+ unsigned long entries = 0, tables = 0;
+
+ /*
+ * Perform a relatively simplistic calculation of the pagetable
+ * entries that are needed. Those mappings will be covered mostly
+ * by 2MB PMD entries so we can conservatively calculate the required
+ * number of P4D, PUD and PMD structures needed to perform the
+ * mappings. For mappings that are not 2MB aligned, PTE mappings
+ * would be needed for the start and end portion of the address range
+ * that fall outside of the 2MB alignment. This results in, at most,
+ * two extra pages to hold PTE entries for each range that is mapped.
+ * Incrementing the count for each covers the case where the addresses
+ * cross entries.
+ */
+
+ /* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */
+ if (PTRS_PER_P4D > 1)
+ entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D;
+ entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD;
+ entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD;
+ entries += 2 * sizeof(pte_t) * PTRS_PER_PTE;
+
+ /*
+ * Now calculate the added pagetable structures needed to populate
+ * the new pagetables.
+ */
+
+ if (PTRS_PER_P4D > 1)
+ tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D;
+ tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD;
+ tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD;
+
+ return entries + tables;
+}
+
+void __init sme_encrypt_kernel(struct boot_params *bp)
+{
+ unsigned long workarea_start, workarea_end, workarea_len;
+ unsigned long execute_start, execute_end, execute_len;
+ unsigned long kernel_start, kernel_end, kernel_len;
+ unsigned long initrd_start, initrd_end, initrd_len;
+ struct sme_populate_pgd_data ppd;
+ unsigned long pgtable_area_len;
+ unsigned long decrypted_base;
+
+ /*
+ * This is early code, use an open coded check for SME instead of
+ * using cc_platform_has(). This eliminates worries about removing
+ * instrumentation or checking boot_cpu_data in the cc_platform_has()
+ * function.
+ */
+ if (!sme_get_me_mask() || sev_status & MSR_AMD64_SEV_ENABLED)
+ return;
+
+ /*
+ * Prepare for encrypting the kernel and initrd by building new
+ * pagetables with the necessary attributes needed to encrypt the
+ * kernel in place.
+ *
+ * One range of virtual addresses will map the memory occupied
+ * by the kernel and initrd as encrypted.
+ *
+ * Another range of virtual addresses will map the memory occupied
+ * by the kernel and initrd as decrypted and write-protected.
+ *
+ * The use of write-protect attribute will prevent any of the
+ * memory from being cached.
+ */
+
+ /* Physical addresses gives us the identity mapped virtual addresses */
+ kernel_start = __pa_symbol(_text);
+ kernel_end = ALIGN(__pa_symbol(_end), PMD_SIZE);
+ kernel_len = kernel_end - kernel_start;
+
+ initrd_start = 0;
+ initrd_end = 0;
+ initrd_len = 0;
+#ifdef CONFIG_BLK_DEV_INITRD
+ initrd_len = (unsigned long)bp->hdr.ramdisk_size |
+ ((unsigned long)bp->ext_ramdisk_size << 32);
+ if (initrd_len) {
+ initrd_start = (unsigned long)bp->hdr.ramdisk_image |
+ ((unsigned long)bp->ext_ramdisk_image << 32);
+ initrd_end = PAGE_ALIGN(initrd_start + initrd_len);
+ initrd_len = initrd_end - initrd_start;
+ }
+#endif
+
+ /*
+ * We're running identity mapped, so we must obtain the address to the
+ * SME encryption workarea using rip-relative addressing.
+ */
+ asm ("lea sme_workarea(%%rip), %0"
+ : "=r" (workarea_start)
+ : "p" (sme_workarea));
+
+ /*
+ * Calculate required number of workarea bytes needed:
+ * executable encryption area size:
+ * stack page (PAGE_SIZE)
+ * encryption routine page (PAGE_SIZE)
+ * intermediate copy buffer (PMD_SIZE)
+ * pagetable structures for the encryption of the kernel
+ * pagetable structures for workarea (in case not currently mapped)
+ */
+ execute_start = workarea_start;
+ execute_end = execute_start + (PAGE_SIZE * 2) + PMD_SIZE;
+ execute_len = execute_end - execute_start;
+
+ /*
+ * One PGD for both encrypted and decrypted mappings and a set of
+ * PUDs and PMDs for each of the encrypted and decrypted mappings.
+ */
+ pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD;
+ pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2;
+ if (initrd_len)
+ pgtable_area_len += sme_pgtable_calc(initrd_len) * 2;
+
+ /* PUDs and PMDs needed in the current pagetables for the workarea */
+ pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len);
+
+ /*
+ * The total workarea includes the executable encryption area and
+ * the pagetable area. The start of the workarea is already 2MB
+ * aligned, align the end of the workarea on a 2MB boundary so that
+ * we don't try to create/allocate PTE entries from the workarea
+ * before it is mapped.
+ */
+ workarea_len = execute_len + pgtable_area_len;
+ workarea_end = ALIGN(workarea_start + workarea_len, PMD_SIZE);
+
+ /*
+ * Set the address to the start of where newly created pagetable
+ * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable
+ * structures are created when the workarea is added to the current
+ * pagetables and when the new encrypted and decrypted kernel
+ * mappings are populated.
+ */
+ ppd.pgtable_area = (void *)execute_end;
+
+ /*
+ * Make sure the current pagetable structure has entries for
+ * addressing the workarea.
+ */
+ ppd.pgd = (pgd_t *)native_read_cr3_pa();
+ ppd.paddr = workarea_start;
+ ppd.vaddr = workarea_start;
+ ppd.vaddr_end = workarea_end;
+ sme_map_range_decrypted(&ppd);
+
+ /* Flush the TLB - no globals so cr3 is enough */
+ native_write_cr3(__native_read_cr3());
+
+ /*
+ * A new pagetable structure is being built to allow for the kernel
+ * and initrd to be encrypted. It starts with an empty PGD that will
+ * then be populated with new PUDs and PMDs as the encrypted and
+ * decrypted kernel mappings are created.
+ */
+ ppd.pgd = ppd.pgtable_area;
+ memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD);
+ ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD;
+
+ /*
+ * A different PGD index/entry must be used to get different
+ * pagetable entries for the decrypted mapping. Choose the next
+ * PGD index and convert it to a virtual address to be used as
+ * the base of the mapping.
+ */
+ decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1);
+ if (initrd_len) {
+ unsigned long check_base;
+
+ check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1);
+ decrypted_base = max(decrypted_base, check_base);
+ }
+ decrypted_base <<= PGDIR_SHIFT;
+
+ /* Add encrypted kernel (identity) mappings */
+ ppd.paddr = kernel_start;
+ ppd.vaddr = kernel_start;
+ ppd.vaddr_end = kernel_end;
+ sme_map_range_encrypted(&ppd);
+
+ /* Add decrypted, write-protected kernel (non-identity) mappings */
+ ppd.paddr = kernel_start;
+ ppd.vaddr = kernel_start + decrypted_base;
+ ppd.vaddr_end = kernel_end + decrypted_base;
+ sme_map_range_decrypted_wp(&ppd);
+
+ if (initrd_len) {
+ /* Add encrypted initrd (identity) mappings */
+ ppd.paddr = initrd_start;
+ ppd.vaddr = initrd_start;
+ ppd.vaddr_end = initrd_end;
+ sme_map_range_encrypted(&ppd);
+ /*
+ * Add decrypted, write-protected initrd (non-identity) mappings
+ */
+ ppd.paddr = initrd_start;
+ ppd.vaddr = initrd_start + decrypted_base;
+ ppd.vaddr_end = initrd_end + decrypted_base;
+ sme_map_range_decrypted_wp(&ppd);
+ }
+
+ /* Add decrypted workarea mappings to both kernel mappings */
+ ppd.paddr = workarea_start;
+ ppd.vaddr = workarea_start;
+ ppd.vaddr_end = workarea_end;
+ sme_map_range_decrypted(&ppd);
+
+ ppd.paddr = workarea_start;
+ ppd.vaddr = workarea_start + decrypted_base;
+ ppd.vaddr_end = workarea_end + decrypted_base;
+ sme_map_range_decrypted(&ppd);
+
+ /* Perform the encryption */
+ sme_encrypt_execute(kernel_start, kernel_start + decrypted_base,
+ kernel_len, workarea_start, (unsigned long)ppd.pgd);
+
+ if (initrd_len)
+ sme_encrypt_execute(initrd_start, initrd_start + decrypted_base,
+ initrd_len, workarea_start,
+ (unsigned long)ppd.pgd);
+
+ /*
+ * At this point we are running encrypted. Remove the mappings for
+ * the decrypted areas - all that is needed for this is to remove
+ * the PGD entry/entries.
+ */
+ ppd.vaddr = kernel_start + decrypted_base;
+ ppd.vaddr_end = kernel_end + decrypted_base;
+ sme_clear_pgd(&ppd);
+
+ if (initrd_len) {
+ ppd.vaddr = initrd_start + decrypted_base;
+ ppd.vaddr_end = initrd_end + decrypted_base;
+ sme_clear_pgd(&ppd);
+ }
+
+ ppd.vaddr = workarea_start + decrypted_base;
+ ppd.vaddr_end = workarea_end + decrypted_base;
+ sme_clear_pgd(&ppd);
+
+ /* Flush the TLB - no globals so cr3 is enough */
+ native_write_cr3(__native_read_cr3());
+}
+
+void __init sme_enable(struct boot_params *bp)
+{
+ const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off;
+ unsigned int eax, ebx, ecx, edx;
+ unsigned long feature_mask;
+ bool active_by_default;
+ unsigned long me_mask;
+ char buffer[16];
+ bool snp;
+ u64 msr;
+
+ 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;
+
+#define AMD_SME_BIT BIT(0)
+#define AMD_SEV_BIT BIT(1)
+
+ /*
+ * 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 or SME is supported */
+ if (!(eax & (AMD_SEV_BIT | AMD_SME_BIT)))
+ return;
+
+ me_mask = 1UL << (ebx & 0x3f);
+
+ /* Check the SEV MSR whether SEV or SME is enabled */
+ sev_status = __rdmsr(MSR_AMD64_SEV);
+ feature_mask = (sev_status & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT;
+
+ /* The SEV-SNP CC blob should never be present unless SEV-SNP is enabled. */
+ if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+ snp_abort();
+
+ /* Check if memory encryption is enabled */
+ if (feature_mask == AMD_SME_BIT) {
+ /*
+ * No SME if Hypervisor bit is set. This check is here to
+ * prevent a guest from trying to enable SME. For running as a
+ * KVM guest the MSR_AMD64_SYSCFG will be sufficient, but there
+ * might be other hypervisors which emulate that MSR as non-zero
+ * or even pass it through to the guest.
+ * A malicious hypervisor can still trick a guest into this
+ * path, but there is no way to protect against that.
+ */
+ eax = 1;
+ ecx = 0;
+ native_cpuid(&eax, &ebx, &ecx, &edx);
+ if (ecx & BIT(31))
+ return;
+
+ /* For SME, check the SYSCFG MSR */
+ msr = __rdmsr(MSR_AMD64_SYSCFG);
+ if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT))
+ return;
+ } else {
+ /* SEV state cannot be controlled by a command line option */
+ sme_me_mask = me_mask;
+ goto out;
+ }
+
+ /*
+ * Fixups have not been applied to phys_base yet and we're running
+ * identity mapped, so we must obtain the address to the SME command
+ * line argument data using rip-relative addressing.
+ */
+ asm ("lea sme_cmdline_arg(%%rip), %0"
+ : "=r" (cmdline_arg)
+ : "p" (sme_cmdline_arg));
+ asm ("lea sme_cmdline_on(%%rip), %0"
+ : "=r" (cmdline_on)
+ : "p" (sme_cmdline_on));
+ asm ("lea sme_cmdline_off(%%rip), %0"
+ : "=r" (cmdline_off)
+ : "p" (sme_cmdline_off));
+
+ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT))
+ active_by_default = true;
+ else
+ active_by_default = false;
+
+ cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
+ ((u64)bp->ext_cmd_line_ptr << 32));
+
+ cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+
+ if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
+ sme_me_mask = me_mask;
+ else if (!strncmp(buffer, cmdline_off, sizeof(buffer)))
+ sme_me_mask = 0;
+ else
+ sme_me_mask = active_by_default ? me_mask : 0;
+out:
+ if (sme_me_mask) {
+ physical_mask &= ~sme_me_mask;
+ cc_set_vendor(CC_VENDOR_AMD);
+ cc_set_mask(sme_me_mask);
+ }
+}