Additional arm64 updates for 4.17

A few late updates to address some issues arising from conflicts with
 other trees:
 
 - Removal of Qualcomm-specific Spectre-v2 mitigation in favour of the
   generic SMCCC-based firmware call
 
 - Fix EL2 hardening capability checking, which was bodged to reduce
   conflicts with the KVM tree
 
 - Add some currently unused assembler macros for managing SIMD registers
   which will be used by some crypto code in the next merge window
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull more arm64 updates from Will Deacon:
 "A few late updates to address some issues arising from conflicts with
  other trees:

   - Removal of Qualcomm-specific Spectre-v2 mitigation in favour of the
     generic SMCCC-based firmware call

   - Fix EL2 hardening capability checking, which was bodged to reduce
     conflicts with the KVM tree

   - Add some currently unused assembler macros for managing SIMD
     registers which will be used by some crypto code in the next merge
     window"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: assembler: add macros to conditionally yield the NEON under PREEMPT
  arm64: assembler: add utility macros to push/pop stack frames
  arm64: Move the content of bpi.S to hyp-entry.S
  arm64: Get rid of __smccc_workaround_1_hvc_*
  arm64: capabilities: Rework EL2 vector hardening entry
  arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening

arch/arm64/include/asm/assembler.h

@@ -565,4 +565,140 @@ USER(\label, ic	ivau, \tmp2)			// invalidate I line PoU
 #endif
 	.endm
 
+	/*
+	 * frame_push - Push @regcount callee saved registers to the stack,
+	 *              starting at x19, as well as x29/x30, and set x29 to
+	 *              the new value of sp. Add @extra bytes of stack space
+	 *              for locals.
+	 */
+	.macro		frame_push, regcount:req, extra
+	__frame		st, \regcount, \extra
+	.endm
+
+	/*
+	 * frame_pop  - Pop the callee saved registers from the stack that were
+	 *              pushed in the most recent call to frame_push, as well
+	 *              as x29/x30 and any extra stack space that may have been
+	 *              allocated.
+	 */
+	.macro		frame_pop
+	__frame		ld
+	.endm
+
+	.macro		__frame_regs, reg1, reg2, op, num
+	.if		.Lframe_regcount == \num
+	\op\()r		\reg1, [sp, #(\num + 1) * 8]
+	.elseif		.Lframe_regcount > \num
+	\op\()p		\reg1, \reg2, [sp, #(\num + 1) * 8]
+	.endif
+	.endm
+
+	.macro		__frame, op, regcount, extra=0
+	.ifc		\op, st
+	.if		(\regcount) < 0 || (\regcount) > 10
+	.error		"regcount should be in the range [0 ... 10]"
+	.endif
+	.if		((\extra) % 16) != 0
+	.error		"extra should be a multiple of 16 bytes"
+	.endif
+	.ifdef		.Lframe_regcount
+	.if		.Lframe_regcount != -1
+	.error		"frame_push/frame_pop may not be nested"
+	.endif
+	.endif
+	.set		.Lframe_regcount, \regcount
+	.set		.Lframe_extra, \extra
+	.set		.Lframe_local_offset, ((\regcount + 3) / 2) * 16
+	stp		x29, x30, [sp, #-.Lframe_local_offset - .Lframe_extra]!
+	mov		x29, sp
+	.endif
+
+	__frame_regs	x19, x20, \op, 1
+	__frame_regs	x21, x22, \op, 3
+	__frame_regs	x23, x24, \op, 5
+	__frame_regs	x25, x26, \op, 7
+	__frame_regs	x27, x28, \op, 9
+
+	.ifc		\op, ld
+	.if		.Lframe_regcount == -1
+	.error		"frame_push/frame_pop may not be nested"
+	.endif
+	ldp		x29, x30, [sp], #.Lframe_local_offset + .Lframe_extra
+	.set		.Lframe_regcount, -1
+	.endif
+	.endm
+
+/*
+ * Check whether to yield to another runnable task from kernel mode NEON code
+ * (which runs with preemption disabled).
+ *
+ * if_will_cond_yield_neon
+ *        // pre-yield patchup code
+ * do_cond_yield_neon
+ *        // post-yield patchup code
+ * endif_yield_neon    <label>
+ *
+ * where <label> is optional, and marks the point where execution will resume
+ * after a yield has been performed. If omitted, execution resumes right after
+ * the endif_yield_neon invocation. Note that the entire sequence, including
+ * the provided patchup code, will be omitted from the image if CONFIG_PREEMPT
+ * is not defined.
+ *
+ * As a convenience, in the case where no patchup code is required, the above
+ * sequence may be abbreviated to
+ *
+ * cond_yield_neon <label>
+ *
+ * Note that the patchup code does not support assembler directives that change
+ * the output section, any use of such directives is undefined.
+ *
+ * The yield itself consists of the following:
+ * - Check whether the preempt count is exactly 1, in which case disabling
+ *   preemption once will make the task preemptible. If this is not the case,
+ *   yielding is pointless.
+ * - Check whether TIF_NEED_RESCHED is set, and if so, disable and re-enable
+ *   kernel mode NEON (which will trigger a reschedule), and branch to the
+ *   yield fixup code.
+ *
+ * This macro sequence may clobber all CPU state that is not guaranteed by the
+ * AAPCS to be preserved across an ordinary function call.
+ */
+
+	.macro		cond_yield_neon, lbl
+	if_will_cond_yield_neon
+	do_cond_yield_neon
+	endif_yield_neon	\lbl
+	.endm
+
+	.macro		if_will_cond_yield_neon
+#ifdef CONFIG_PREEMPT
+	get_thread_info	x0
+	ldr		w1, [x0, #TSK_TI_PREEMPT]
+	ldr		x0, [x0, #TSK_TI_FLAGS]
+	cmp		w1, #PREEMPT_DISABLE_OFFSET
+	csel		x0, x0, xzr, eq
+	tbnz		x0, #TIF_NEED_RESCHED, .Lyield_\@	// needs rescheduling?
+	/* fall through to endif_yield_neon */
+	.subsection	1
+.Lyield_\@ :
+#else
+	.section	".discard.cond_yield_neon", "ax"
+#endif
+	.endm
+
+	.macro		do_cond_yield_neon
+	bl		kernel_neon_end
+	bl		kernel_neon_begin
+	.endm
+
+	.macro		endif_yield_neon, lbl
+	.ifnb		\lbl
+	b		\lbl
+	.else
+	b		.Lyield_out_\@
+	.endif
+	.previous
+.Lyield_out_\@ :
+	.endm
+
 #endif	/* __ASM_ASSEMBLER_H */

arch/arm64/include/asm/cpucaps.h

@@ -43,13 +43,12 @@
 #define ARM64_SVE				22
 #define ARM64_UNMAP_KERNEL_AT_EL0		23
 #define ARM64_HARDEN_BRANCH_PREDICTOR		24
-#define ARM64_HARDEN_BP_POST_GUEST_EXIT		25
+#define ARM64_HAS_RAS_EXTN			25
-#define ARM64_HAS_RAS_EXTN			26
+#define ARM64_WORKAROUND_843419			26
-#define ARM64_WORKAROUND_843419			27
+#define ARM64_HAS_CACHE_IDC			27
-#define ARM64_HAS_CACHE_IDC			28
+#define ARM64_HAS_CACHE_DIC			28
-#define ARM64_HAS_CACHE_DIC			29
+#define ARM64_HW_DBM				29
-#define ARM64_HW_DBM				30
 
-#define ARM64_NCAPS				31
+#define ARM64_NCAPS				30
 
 #endif /* __ASM_CPUCAPS_H */

arch/arm64/include/asm/kvm_asm.h

@@ -71,8 +71,6 @@ extern u32 __kvm_get_mdcr_el2(void);
 
 extern u32 __init_stage2_translation(void);
 
-extern void __qcom_hyp_sanitize_btac_predictors(void);
-
 #else /* __ASSEMBLY__ */
 
 .macro get_host_ctxt reg, tmp

arch/arm64/kernel/Makefile

@@ -55,8 +55,6 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o
 arm64-obj-$(CONFIG_CRASH_DUMP)		+= crash_dump.o
 arm64-obj-$(CONFIG_ARM_SDE_INTERFACE)	+= sdei.o
 
-arm64-obj-$(CONFIG_KVM_INDIRECT_VECTORS)+= bpi.o
-
 obj-y					+= $(arm64-obj-y) vdso/ probes/
 obj-m					+= $(arm64-obj-m)
 head-y					:= head.o

arch/arm64/kernel/asm-offsets.c

@@ -23,6 +23,7 @@
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
 #include <linux/kvm_host.h>
+#include <linux/preempt.h>
 #include <linux/suspend.h>
 #include <asm/cpufeature.h>
 #include <asm/fixmap.h>
@@ -93,6 +94,8 @@ int main(void)
   DEFINE(DMA_TO_DEVICE,		DMA_TO_DEVICE);
   DEFINE(DMA_FROM_DEVICE,	DMA_FROM_DEVICE);
   BLANK();
+  DEFINE(PREEMPT_DISABLE_OFFSET, PREEMPT_DISABLE_OFFSET);
+  BLANK();
   DEFINE(CLOCK_REALTIME,	CLOCK_REALTIME);
   DEFINE(CLOCK_MONOTONIC,	CLOCK_MONOTONIC);
   DEFINE(CLOCK_MONOTONIC_RAW,	CLOCK_MONOTONIC_RAW);

arch/arm64/kernel/bpi.S

@@ -1,102 +0,0 @@
-/*
- * Contains CPU specific branch predictor invalidation sequences
- *
- * Copyright (C) 2018 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <linux/linkage.h>
-#include <linux/arm-smccc.h>
-
-#include <asm/alternative.h>
-#include <asm/mmu.h>
-
-.macro hyp_ventry
-	.align 7
-1:	.rept 27
-	nop
-	.endr
-/*
- * The default sequence is to directly branch to the KVM vectors,
- * using the computed offset. This applies for VHE as well as
- * !ARM64_HARDEN_EL2_VECTORS.
- *
- * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced
- * with:
- *
- * stp	x0, x1, [sp, #-16]!
- * movz	x0, #(addr & 0xffff)
- * movk	x0, #((addr >> 16) & 0xffff), lsl #16
- * movk	x0, #((addr >> 32) & 0xffff), lsl #32
- * br	x0
- *
- * Where addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + 4.
- * See kvm_patch_vector_branch for details.
- */
-alternative_cb	kvm_patch_vector_branch
-	b	__kvm_hyp_vector + (1b - 0b)
-	nop
-	nop
-	nop
-	nop
-alternative_cb_end
-.endm
-
-.macro generate_vectors
-0:
-	.rept 16
-	hyp_ventry
-	.endr
-	.org 0b + SZ_2K		// Safety measure
-.endm
-
-
-	.text
-	.pushsection	.hyp.text, "ax"
-
-	.align	11
-ENTRY(__bp_harden_hyp_vecs_start)
-	.rept BP_HARDEN_EL2_SLOTS
-	generate_vectors
-	.endr
-ENTRY(__bp_harden_hyp_vecs_end)
-
-	.popsection
-
-ENTRY(__qcom_hyp_sanitize_link_stack_start)
-	stp     x29, x30, [sp, #-16]!
-	.rept	16
-	bl	. + 4
-	.endr
-	ldp	x29, x30, [sp], #16
-ENTRY(__qcom_hyp_sanitize_link_stack_end)
-
-.macro smccc_workaround_1 inst
-	sub	sp, sp, #(8 * 4)
-	stp	x2, x3, [sp, #(8 * 0)]
-	stp	x0, x1, [sp, #(8 * 2)]
-	mov	w0, #ARM_SMCCC_ARCH_WORKAROUND_1
-	\inst	#0
-	ldp	x2, x3, [sp, #(8 * 0)]
-	ldp	x0, x1, [sp, #(8 * 2)]
-	add	sp, sp, #(8 * 4)
-.endm
-
-ENTRY(__smccc_workaround_1_smc_start)
-	smccc_workaround_1	smc
-ENTRY(__smccc_workaround_1_smc_end)
-
-ENTRY(__smccc_workaround_1_hvc_start)
-	smccc_workaround_1	hvc
-ENTRY(__smccc_workaround_1_hvc_end)

arch/arm64/kernel/cpu_errata.c

@@ -86,13 +86,9 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1);
 
 DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
 
-#ifdef CONFIG_KVM
+#ifdef CONFIG_KVM_INDIRECT_VECTORS
-extern char __qcom_hyp_sanitize_link_stack_start[];
-extern char __qcom_hyp_sanitize_link_stack_end[];
 extern char __smccc_workaround_1_smc_start[];
 extern char __smccc_workaround_1_smc_end[];
-extern char __smccc_workaround_1_hvc_start[];
-extern char __smccc_workaround_1_hvc_end[];
 
 static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
 				const char *hyp_vecs_end)
@@ -132,12 +128,8 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
 	spin_unlock(&bp_lock);
 }
 #else
-#define __qcom_hyp_sanitize_link_stack_start	NULL
-#define __qcom_hyp_sanitize_link_stack_end	NULL
 #define __smccc_workaround_1_smc_start		NULL
 #define __smccc_workaround_1_smc_end		NULL
-#define __smccc_workaround_1_hvc_start		NULL
-#define __smccc_workaround_1_hvc_end		NULL
 
 static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
 				      const char *hyp_vecs_start,
@@ -145,7 +137,7 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn,
 {
 	__this_cpu_write(bp_hardening_data.fn, fn);
 }
-#endif	/* CONFIG_KVM */
+#endif	/* CONFIG_KVM_INDIRECT_VECTORS */
 
 static void  install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry,
 				     bp_hardening_cb_t fn,
@@ -178,12 +170,25 @@ static void call_hvc_arch_workaround_1(void)
 	arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL);
 }
 
+static void qcom_link_stack_sanitization(void)
+{
+	u64 tmp;
+
+	asm volatile("mov	%0, x30		\n"
+		     ".rept	16		\n"
+		     "bl	. + 4		\n"
+		     ".endr			\n"
+		     "mov	x30, %0		\n"
+		     : "=&r" (tmp));
+}
+
 static void
 enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
 {
 	bp_hardening_cb_t cb;
 	void *smccc_start, *smccc_end;
 	struct arm_smccc_res res;
+	u32 midr = read_cpuid_id();
 
 	if (!entry->matches(entry, SCOPE_LOCAL_CPU))
 		return;
@@ -198,8 +203,9 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
 		if ((int)res.a0 < 0)
 			return;
 		cb = call_hvc_arch_workaround_1;
-		smccc_start = __smccc_workaround_1_hvc_start;
+		/* This is a guest, no need to patch KVM vectors */
-		smccc_end = __smccc_workaround_1_hvc_end;
+		smccc_start = NULL;
+		smccc_end = NULL;
 		break;
 
 	case PSCI_CONDUIT_SMC:
@@ -216,30 +222,14 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry)
 		return;
 	}
 
+	if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) ||
+	    ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1))
+		cb = qcom_link_stack_sanitization;
+
 	install_bp_hardening_cb(entry, cb, smccc_start, smccc_end);
 
 	return;
 }
-
-static void qcom_link_stack_sanitization(void)
-{
-	u64 tmp;
-
-	asm volatile("mov	%0, x30		\n"
-		     ".rept	16		\n"
-		     "bl	. + 4		\n"
-		     ".endr			\n"
-		     "mov	x30, %0		\n"
-		     : "=&r" (tmp));
-}
-
-static void
-qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry)
-{
-	install_bp_hardening_cb(entry, qcom_link_stack_sanitization,
-				__qcom_hyp_sanitize_link_stack_start,
-				__qcom_hyp_sanitize_link_stack_end);
-}
 #endif	/* CONFIG_HARDEN_BRANCH_PREDICTOR */
 
 #define CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max)	\
@@ -324,33 +314,23 @@ static const struct midr_range arm64_bp_harden_smccc_cpus[] = {
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
 	MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
 	MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
-	{},
-};
-
-static const struct midr_range qcom_bp_harden_cpus[] = {
 	MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
 	MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
 	{},
 };
 
-static const struct arm64_cpu_capabilities arm64_bp_harden_list[] = {
+#endif
-	{
+
-		CAP_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus),
+#ifdef CONFIG_HARDEN_EL2_VECTORS
-		.cpu_enable = enable_smccc_arch_workaround_1,
+
-	},
+static const struct midr_range arm64_harden_el2_vectors[] = {
-	{
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
-		CAP_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
-		.cpu_enable = qcom_enable_link_stack_sanitization,
-	},
 	{},
 };
 
 #endif
 
-#ifndef ERRATA_MIDR_ALL_VERSIONS
-#define	ERRATA_MIDR_ALL_VERSIONS(x)	MIDR_ALL_VERSIONS(x)
-#endif
-
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #if	defined(CONFIG_ARM64_ERRATUM_826319) || \
 	defined(CONFIG_ARM64_ERRATUM_827319) || \
@@ -495,25 +475,16 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 	{
 		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
-		.matches = multi_entry_cap_matches,
+		.cpu_enable = enable_smccc_arch_workaround_1,
-		.cpu_enable = multi_entry_cap_cpu_enable,
+		ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus),
-		.match_list = arm64_bp_harden_list,
-	},
-	{
-		.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
-		ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
 	},
 #endif
 #ifdef CONFIG_HARDEN_EL2_VECTORS
 	{
-		.desc = "Cortex-A57 EL2 vector hardening",
+		.desc = "EL2 vector hardening",
 		.capability = ARM64_HARDEN_EL2_VECTORS,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
+		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
-	},
+		ERRATA_MIDR_RANGE_LIST(arm64_harden_el2_vectors),
-	{
-		.desc = "Cortex-A72 EL2 vector hardening",
-		.capability = ARM64_HARDEN_EL2_VECTORS,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
 	},
 #endif
 	{

arch/arm64/kvm/hyp/entry.S

@@ -209,15 +209,3 @@ alternative_endif
 
 	eret
 ENDPROC(__fpsimd_guest_restore)
-
-ENTRY(__qcom_hyp_sanitize_btac_predictors)
-	/**
-	 * Call SMC64 with Silicon provider serviceID 23<<8 (0xc2001700)
-	 * 0xC2000000-0xC200FFFF: assigned to SiP Service Calls
-	 * b15-b0: contains SiP functionID
-	 */
-	movz    x0, #0x1700
-	movk    x0, #0xc200, lsl #16
-	smc     #0
-	ret
-ENDPROC(__qcom_hyp_sanitize_btac_predictors)

arch/arm64/kvm/hyp/hyp-entry.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 - ARM Ltd
+ * Copyright (C) 2015-2018 - ARM Ltd
  * Author: Marc Zyngier <marc.zyngier@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -24,6 +24,7 @@
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmu.h>
+#include <asm/mmu.h>
 
 	.text
 	.pushsection	.hyp.text, "ax"
@@ -237,3 +238,64 @@ ENTRY(__kvm_hyp_vector)
 	invalid_vect	el1_fiq_invalid		// FIQ 32-bit EL1
 	valid_vect	el1_error		// Error 32-bit EL1
 ENDPROC(__kvm_hyp_vector)
+
+#ifdef CONFIG_KVM_INDIRECT_VECTORS
+.macro hyp_ventry
+	.align 7
+1:	.rept 27
+	nop
+	.endr
+/*
+ * The default sequence is to directly branch to the KVM vectors,
+ * using the computed offset. This applies for VHE as well as
+ * !ARM64_HARDEN_EL2_VECTORS.
+ *
+ * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced
+ * with:
+ *
+ * stp	x0, x1, [sp, #-16]!
+ * movz	x0, #(addr & 0xffff)
+ * movk	x0, #((addr >> 16) & 0xffff), lsl #16
+ * movk	x0, #((addr >> 32) & 0xffff), lsl #32
+ * br	x0
+ *
+ * Where addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + 4.
+ * See kvm_patch_vector_branch for details.
+ */
+alternative_cb	kvm_patch_vector_branch
+	b	__kvm_hyp_vector + (1b - 0b)
+	nop
+	nop
+	nop
+	nop
+alternative_cb_end
+.endm
+
+.macro generate_vectors
+0:
+	.rept 16
+	hyp_ventry
+	.endr
+	.org 0b + SZ_2K		// Safety measure
+.endm
+
+	.align	11
+ENTRY(__bp_harden_hyp_vecs_start)
+	.rept BP_HARDEN_EL2_SLOTS
+	generate_vectors
+	.endr
+ENTRY(__bp_harden_hyp_vecs_end)
+
+	.popsection
+
+ENTRY(__smccc_workaround_1_smc_start)
+	sub	sp, sp, #(8 * 4)
+	stp	x2, x3, [sp, #(8 * 0)]
+	stp	x0, x1, [sp, #(8 * 2)]
+	mov	w0, #ARM_SMCCC_ARCH_WORKAROUND_1
+	smc	#0
+	ldp	x2, x3, [sp, #(8 * 0)]
+	ldp	x0, x1, [sp, #(8 * 2)]
+	add	sp, sp, #(8 * 4)
+ENTRY(__smccc_workaround_1_smc_end)
+#endif

arch/arm64/kvm/hyp/switch.c

@@ -472,16 +472,6 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
 		/* And we're baaack! */
 	} while (fixup_guest_exit(vcpu, &exit_code));
 
-	if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) {
-		u32 midr = read_cpuid_id();
-
-		/* Apply BTAC predictors mitigation to all Falkor chips */
-		if (((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR) ||
-		    ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1)) {
-			__qcom_hyp_sanitize_btac_predictors();
-		}
-	}
-
 	fp_enabled = __fpsimd_enabled_nvhe();
 
 	__sysreg_save_state_nvhe(guest_ctxt);