Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 298 insertions, 0 deletions

diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
new file mode 100644
index 0000000000..91b22a0146
--- /dev/null
+++ b/arch/arm64/kvm/va_layout.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/random.h>
+#include <linux/memblock.h>
+#include <asm/alternative.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
+#include <asm/kvm_mmu.h>
+#include <asm/memory.h>
+
+/*
+ * The LSB of the HYP VA tag
+ */
+static u8 tag_lsb;
+/*
+ * The HYP VA tag value with the region bit
+ */
+static u64 tag_val;
+static u64 va_mask;
+
+/*
+ * Compute HYP VA by using the same computation as kern_hyp_va().
+ */
+static u64 __early_kern_hyp_va(u64 addr)
+{
+	addr &= va_mask;
+	addr |= tag_val << tag_lsb;
+	return addr;
+}
+
+/*
+ * Store a hyp VA <-> PA offset into a EL2-owned variable.
+ */
+static void init_hyp_physvirt_offset(void)
+{
+	u64 kern_va, hyp_va;
+
+	/* Compute the offset from the hyp VA and PA of a random symbol. */
+	kern_va = (u64)lm_alias(__hyp_text_start);
+	hyp_va = __early_kern_hyp_va(kern_va);
+	hyp_physvirt_offset = (s64)__pa(kern_va) - (s64)hyp_va;
+}
+
+/*
+ * We want to generate a hyp VA with the following format (with V ==
+ * vabits_actual):
+ *
+ *  63 ... V |     V-1    | V-2 .. tag_lsb | tag_lsb - 1 .. 0
+ *  ---------------------------------------------------------
+ * | 0000000 | hyp_va_msb |   random tag   |  kern linear VA |
+ *           |--------- tag_val -----------|----- va_mask ---|
+ *
+ * which does not conflict with the idmap regions.
+ */
+__init void kvm_compute_layout(void)
+{
+	phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);
+	u64 hyp_va_msb;
+
+	/* Where is my RAM region? */
+	hyp_va_msb  = idmap_addr & BIT(vabits_actual - 1);
+	hyp_va_msb ^= BIT(vabits_actual - 1);
+
+	tag_lsb = fls64((u64)phys_to_virt(memblock_start_of_DRAM()) ^
+			(u64)(high_memory - 1));
+
+	va_mask = GENMASK_ULL(tag_lsb - 1, 0);
+	tag_val = hyp_va_msb;
+
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) {
+		/* We have some free bits to insert a random tag. */
+		tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb);
+	}
+	tag_val >>= tag_lsb;
+
+	init_hyp_physvirt_offset();
+}
+
+/*
+ * The .hyp.reloc ELF section contains a list of kimg positions that
+ * contains kimg VAs but will be accessed only in hyp execution context.
+ * Convert them to hyp VAs. See gen-hyprel.c for more details.
+ */
+__init void kvm_apply_hyp_relocations(void)
+{
+	int32_t *rel;
+	int32_t *begin = (int32_t *)__hyp_reloc_begin;
+	int32_t *end = (int32_t *)__hyp_reloc_end;
+
+	for (rel = begin; rel < end; ++rel) {
+		uintptr_t *ptr, kimg_va;
+
+		/*
+		 * Each entry contains a 32-bit relative offset from itself
+		 * to a kimg VA position.
+		 */
+		ptr = (uintptr_t *)lm_alias((char *)rel + *rel);
+
+		/* Read the kimg VA value at the relocation address. */
+		kimg_va = *ptr;
+
+		/* Convert to hyp VA and store back to the relocation address. */
+		*ptr = __early_kern_hyp_va((uintptr_t)lm_alias(kimg_va));
+	}
+}
+
+static u32 compute_instruction(int n, u32 rd, u32 rn)
+{
+	u32 insn = AARCH64_BREAK_FAULT;
+
+	switch (n) {
+	case 0:
+		insn = aarch64_insn_gen_logical_immediate(AARCH64_INSN_LOGIC_AND,
+							  AARCH64_INSN_VARIANT_64BIT,
+							  rn, rd, va_mask);
+		break;
+
+	case 1:
+		/* ROR is a variant of EXTR with Rm = Rn */
+		insn = aarch64_insn_gen_extr(AARCH64_INSN_VARIANT_64BIT,
+					     rn, rn, rd,
+					     tag_lsb);
+		break;
+
+	case 2:
+		insn = aarch64_insn_gen_add_sub_imm(rd, rn,
+						    tag_val & GENMASK(11, 0),
+						    AARCH64_INSN_VARIANT_64BIT,
+						    AARCH64_INSN_ADSB_ADD);
+		break;
+
+	case 3:
+		insn = aarch64_insn_gen_add_sub_imm(rd, rn,
+						    tag_val & GENMASK(23, 12),
+						    AARCH64_INSN_VARIANT_64BIT,
+						    AARCH64_INSN_ADSB_ADD);
+		break;
+
+	case 4:
+		/* ROR is a variant of EXTR with Rm = Rn */
+		insn = aarch64_insn_gen_extr(AARCH64_INSN_VARIANT_64BIT,
+					     rn, rn, rd, 64 - tag_lsb);
+		break;
+	}
+
+	return insn;
+}
+
+void __init kvm_update_va_mask(struct alt_instr *alt,
+			       __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	int i;
+
+	BUG_ON(nr_inst != 5);
+
+	for (i = 0; i < nr_inst; i++) {
+		u32 rd, rn, insn, oinsn;
+
+		/*
+		 * VHE doesn't need any address translation, let's NOP
+		 * everything.
+		 *
+		 * Alternatively, if the tag is zero (because the layout
+		 * dictates it and we don't have any spare bits in the
+		 * address), NOP everything after masking the kernel VA.
+		 */
+		if (cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN) || (!tag_val && i > 0)) {
+			updptr[i] = cpu_to_le32(aarch64_insn_gen_nop());
+			continue;
+		}
+
+		oinsn = le32_to_cpu(origptr[i]);
+		rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn);
+		rn = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RN, oinsn);
+
+		insn = compute_instruction(i, rd, rn);
+		BUG_ON(insn == AARCH64_BREAK_FAULT);
+
+		updptr[i] = cpu_to_le32(insn);
+	}
+}
+
+void kvm_patch_vector_branch(struct alt_instr *alt,
+			     __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	u64 addr;
+	u32 insn;
+
+	BUG_ON(nr_inst != 4);
+
+	if (!cpus_have_cap(ARM64_SPECTRE_V3A) ||
+	    WARN_ON_ONCE(cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN)))
+		return;
+
+	/*
+	 * Compute HYP VA by using the same computation as kern_hyp_va()
+	 */
+	addr = __early_kern_hyp_va((u64)kvm_ksym_ref(__kvm_hyp_vector));
+
+	/* Use PC[10:7] to branch to the same vector in KVM */
+	addr |= ((u64)origptr & GENMASK_ULL(10, 7));
+
+	/*
+	 * Branch over the preamble in order to avoid the initial store on
+	 * the stack (which we already perform in the hardening vectors).
+	 */
+	addr += KVM_VECTOR_PREAMBLE;
+
+	/* movz x0, #(addr & 0xffff) */
+	insn = aarch64_insn_gen_movewide(AARCH64_INSN_REG_0,
+					 (u16)addr,
+					 0,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_ZERO);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk x0, #((addr >> 16) & 0xffff), lsl #16 */
+	insn = aarch64_insn_gen_movewide(AARCH64_INSN_REG_0,
+					 (u16)(addr >> 16),
+					 16,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk x0, #((addr >> 32) & 0xffff), lsl #32 */
+	insn = aarch64_insn_gen_movewide(AARCH64_INSN_REG_0,
+					 (u16)(addr >> 32),
+					 32,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* br x0 */
+	insn = aarch64_insn_gen_branch_reg(AARCH64_INSN_REG_0,
+					   AARCH64_INSN_BRANCH_NOLINK);
+	*updptr++ = cpu_to_le32(insn);
+}
+
+static void generate_mov_q(u64 val, __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	u32 insn, oinsn, rd;
+
+	BUG_ON(nr_inst != 4);
+
+	/* Compute target register */
+	oinsn = le32_to_cpu(*origptr);
+	rd = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RD, oinsn);
+
+	/* movz rd, #(val & 0xffff) */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)val,
+					 0,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_ZERO);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk rd, #((val >> 16) & 0xffff), lsl #16 */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)(val >> 16),
+					 16,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk rd, #((val >> 32) & 0xffff), lsl #32 */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)(val >> 32),
+					 32,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+
+	/* movk rd, #((val >> 48) & 0xffff), lsl #48 */
+	insn = aarch64_insn_gen_movewide(rd,
+					 (u16)(val >> 48),
+					 48,
+					 AARCH64_INSN_VARIANT_64BIT,
+					 AARCH64_INSN_MOVEWIDE_KEEP);
+	*updptr++ = cpu_to_le32(insn);
+}
+
+void kvm_get_kimage_voffset(struct alt_instr *alt,
+			    __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	generate_mov_q(kimage_voffset, origptr, updptr, nr_inst);
+}
+
+void kvm_compute_final_ctr_el0(struct alt_instr *alt,
+			       __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+	generate_mov_q(read_sanitised_ftr_reg(SYS_CTR_EL0),
+		       origptr, updptr, nr_inst);
+}