Thread (51 messages) 51 messages, 8 authors, 2018-05-24

[PATCH 11/14] arm64: KVM: Add HYP per-cpu accessors

From: mark.rutland@arm.com (Mark Rutland)
Date: 2018-05-24 12:11:43
Also in: kvmarm, lkml

On Tue, May 22, 2018 at 04:06:45PM +0100, Marc Zyngier wrote:
As we're going to require to access per-cpu variables at EL2,
let's craft the minimum set of accessors required to implement
reading a per-cpu variable, relying on tpidr_el2 to contain the
per-cpu offset.

Reviewed-by: Christoffer Dall <redacted>
Signed-off-by: Marc Zyngier <redacted>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Mark.
quoted hunk ↗ jump to hunk
---
 arch/arm64/include/asm/kvm_asm.h | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index f6648a3e4152..fefd8cf42c35 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -71,14 +71,37 @@ extern u32 __kvm_get_mdcr_el2(void);
 
 extern u32 __init_stage2_translation(void);
 
+/* Home-grown __this_cpu_{ptr,read} variants that always work at HYP */
+#define __hyp_this_cpu_ptr(sym)						\
+	({								\
+		void *__ptr = hyp_symbol_addr(sym);			\
+		__ptr += read_sysreg(tpidr_el2);			\
+		(typeof(&sym))__ptr;					\
+	 })
+
+#define __hyp_this_cpu_read(sym)					\
+	({								\
+		*__hyp_this_cpu_ptr(sym);				\
+	 })
+
 #else /* __ASSEMBLY__ */
 
-.macro get_host_ctxt reg, tmp
-	adr_l	\reg, kvm_host_cpu_state
+.macro hyp_adr_this_cpu reg, sym, tmp
+	adr_l	\reg, \sym
 	mrs	\tmp, tpidr_el2
 	add	\reg, \reg, \tmp
 .endm
 
+.macro hyp_ldr_this_cpu reg, sym, tmp
+	adr_l	\reg, \sym
+	mrs	\tmp, tpidr_el2
+	ldr	\reg,  [\reg, \tmp]
+.endm
+
+.macro get_host_ctxt reg, tmp
+	hyp_adr_this_cpu \reg, kvm_host_cpu_state, \tmp
+.endm
+
 .macro get_vcpu_ptr vcpu, ctxt
 	get_host_ctxt \ctxt, \vcpu
 	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
-- 
2.14.2
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help