Merge "KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated" (9bf24a89) · Commits · e / devices / android_kernel_fairphone_FP4

arch/arm/include/asm/kvm_host.h

+7 −0

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		@@ -26,6 +26,7 @@
		#include <asm/kvm_asm.h>
		#include <asm/kvm_mmio.h>
		#include <asm/fpstate.h>
		#include <asm/spectre.h>
		#include <kvm/arm_arch_timer.h>

		#define __KVM_HAVE_ARCH_INTC_INITIALIZED
		@@ -366,4 +367,10 @@ void kvm_arch_free_vm(struct kvm *kvm);

		#define kvm_arm_vcpu_loaded(vcpu) (false)

		static inline int kvm_arm_get_spectre_bhb_state(void)
		{
		/* 32bit guests don't need firmware for this */
		return SPECTRE_VULNERABLE; /* aka SMCCC_RET_NOT_SUPPORTED */
		}

		#endif /* __ARM_KVM_HOST_H__ */

+9 −0

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		@@ -1152,6 +1152,15 @@ config COMPAT_VDSO
		You must have a 32-bit build of glibc 2.22 or later for programs
		to seamlessly take advantage of this.

		config MITIGATE_SPECTRE_BRANCH_HISTORY
		bool "Mitigate Spectre style attacks against branch history" if EXPERT
		default y
		help
		Speculation attacks against some high-performance processors can
		make use of branch history to influence future speculation.
		When taking an exception from user-space, a sequence of branches
		or a firmware call overwrites the branch history.

		menuconfig ARMV8_DEPRECATED
		bool "Emulate deprecated/obsolete ARMv8 instructions"
		depends on COMPAT

+27 −0

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		@@ -732,4 +732,31 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU
		.Lyield_out_\@ :
		.endm

		.macro __mitigate_spectre_bhb_loop tmp
		#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
		alternative_cb spectre_bhb_patch_loop_iter
		mov \tmp, #32 // Patched to correct the immediate
		alternative_cb_end
		.Lspectre_bhb_loop\@:
		b . + 4
		subs \tmp, \tmp, #1
		b.ne .Lspectre_bhb_loop\@
		dsb nsh
		isb
		#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
		.endm

		/* Save/restores x0-x3 to the stack */
		.macro __mitigate_spectre_bhb_fw
		#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
		stp x0, x1, [sp, #-16]!
		stp x2, x3, [sp, #-16]!
		mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3
		alternative_cb arm64_update_smccc_conduit
		nop // Patched to SMC/HVC #0
		alternative_cb_end
		ldp x2, x3, [sp], #16
		ldp x0, x1, [sp], #16
		#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
		.endm
		#endif /* __ASM_ASSEMBLER_H */

+1 −0

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		@@ -56,6 +56,7 @@
		#define ARM64_WORKAROUND_1188873 35
		#define ARM64_WORKAROUND_1542418 36
		#define ARM64_WORKAROUND_1542419 37
		#define ARM64_SPECTRE_BHB 38

		/* kabi: reserve 38 - 62 for future cpu capabilities */
		#define ARM64_NCAPS 62

+27 −0

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		@@ -482,6 +482,21 @@ static inline bool cpu_supports_mixed_endian_el0(void)
		return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
		}

		static inline bool supports_csv2p3(int scope)
		{
		u64 pfr0;
		u8 csv2_val;

		if (scope == SCOPE_LOCAL_CPU)
		pfr0 = read_sysreg_s(SYS_ID_AA64PFR0_EL1);
		else
		pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);

		csv2_val = cpuid_feature_extract_unsigned_field(pfr0,
		ID_AA64PFR0_CSV2_SHIFT);
		return csv2_val == 3;
		}

		static inline bool system_supports_32bit_el0(void)
		{
		return cpus_have_const_cap(ARM64_HAS_32BIT_EL0);
		@@ -532,6 +547,18 @@ static inline int arm64_get_ssbd_state(void)

		void arm64_set_ssbd_mitigation(bool state);

		/* Watch out, ordering is important here. */
		enum mitigation_state {
		SPECTRE_UNAFFECTED,
		SPECTRE_MITIGATED,
		SPECTRE_VULNERABLE,
		};

		enum mitigation_state arm64_get_spectre_bhb_state(void);
		bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope);
		u8 spectre_bhb_loop_affected(int scope);
		void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *__unused);

		#endif /* __ASSEMBLY__ */

		#endif