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authorAndrew Scull <ascull@google.com>2020-09-15 13:46:35 +0300
committerMarc Zyngier <maz@kernel.org>2020-09-15 20:39:03 +0300
commit603d2bdaa57e48a33d57eeb88971b88fbe5875d6 (patch)
treea2fe55c4eb971c4040c651ff51ad094a9bb6c4cf /arch/arm64/include/asm/kvm_asm.h
parent7db21530479f071ee0e0a4d5fcf5e6bc6c0352ba (diff)
downloadlinux-603d2bdaa57e48a33d57eeb88971b88fbe5875d6.tar.xz
KVM: arm64: Share context save and restore macros
To avoid duplicating the context save and restore macros, move them into a shareable header. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-12-ascull@google.com
Diffstat (limited to 'arch/arm64/include/asm/kvm_asm.h')
-rw-r--r--arch/arm64/include/asm/kvm_asm.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 4df2bd8882bc..4e3073858346 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -261,6 +261,45 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];
.popsection
.endm
+#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x)
+#define CPU_LR_OFFSET CPU_XREG_OFFSET(30)
+#define CPU_SP_EL0_OFFSET (CPU_LR_OFFSET + 8)
+
+/*
+ * We treat x18 as callee-saved as the host may use it as a platform
+ * register (e.g. for shadow call stack).
+ */
+.macro save_callee_saved_regs ctxt
+ str x18, [\ctxt, #CPU_XREG_OFFSET(18)]
+ stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
+ stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
+ stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
+ stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
+ stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
+ stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
+.endm
+
+.macro restore_callee_saved_regs ctxt
+ // We require \ctxt is not x18-x28
+ ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)]
+ ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
+ ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
+ ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
+ ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
+ ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
+ ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
+.endm
+
+.macro save_sp_el0 ctxt, tmp
+ mrs \tmp, sp_el0
+ str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
+.endm
+
+.macro restore_sp_el0 ctxt, tmp
+ ldr \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
+ msr sp_el0, \tmp
+.endm
+
#endif
#endif /* __ARM_KVM_ASM_H__ */