[PATCH v2 04/21] arm64: KVM: Implement vgic-v3 save/restore

Marc Zyngier marc.zyngier at arm.com
Fri Nov 27 10:49:58 PST 2015


Implement the vgic-v3 save restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
 arch/arm64/kvm/hyp/Makefile     |   1 +
 arch/arm64/kvm/hyp/hyp.h        |   3 +
 arch/arm64/kvm/hyp/vgic-v3-sr.c | 222 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 226 insertions(+)
 create mode 100644 arch/arm64/kvm/hyp/vgic-v3-sr.c

diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index d8d5968..d1e38ce 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o
diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
index 78f25c4..a31cb6e 100644
--- a/arch/arm64/kvm/hyp/hyp.h
+++ b/arch/arm64/kvm/hyp/hyp.h
@@ -30,5 +30,8 @@
 void __vgic_v2_save_state(struct kvm_vcpu *vcpu);
 void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);
 
+void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
+void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
+
 #endif /* __ARM64_KVM_HYP_H__ */
 
diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
new file mode 100644
index 0000000..b490db5
--- /dev/null
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier at arm.com>
+ *
+ * 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/compiler.h>
+#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_mmu.h>
+
+#include "hyp.h"
+
+/*
+ * We store LRs in reverse order to let the CPU deal with streaming
+ * access. Use this macro to make it look saner...
+ */
+#define LR_OFFSET(n)	(15 - n)
+
+#define read_gicreg(r)							\
+	({								\
+		u64 reg;						\
+		asm volatile("mrs_s %0, " __stringify(r) : "=r" (reg));	\
+		reg;							\
+	})
+
+#define write_gicreg(v,r)						\
+	do {								\
+		u64 __val = (v);					\
+		asm volatile("msr_s " __stringify(r) ", %0" : : "r" (__val));\
+	} while (0)
+
+/* vcpu is already in the HYP VA space */
+void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+	u64 val;
+	u32 nr_lr, nr_pri;
+
+	/*
+	 * Make sure stores to the GIC via the memory mapped interface
+	 * are now visible to the system register interface.
+	 */
+	dsb(st);
+
+	cpu_if->vgic_vmcr  = read_gicreg(ICH_VMCR_EL2);
+	cpu_if->vgic_misr  = read_gicreg(ICH_MISR_EL2);
+	cpu_if->vgic_eisr  = read_gicreg(ICH_EISR_EL2);
+	cpu_if->vgic_elrsr = read_gicreg(ICH_ELSR_EL2);
+
+	write_gicreg(0, ICH_HCR_EL2);
+	val = read_gicreg(ICH_VTR_EL2);
+	nr_lr = val & 0xf;
+	nr_pri = ((u32)val >> 29) + 1;
+
+	switch (nr_lr) {
+	case 15:
+		cpu_if->vgic_lr[LR_OFFSET(15)] = read_gicreg(ICH_LR15_EL2);
+	case 14:
+		cpu_if->vgic_lr[LR_OFFSET(14)] = read_gicreg(ICH_LR14_EL2);
+	case 13:
+		cpu_if->vgic_lr[LR_OFFSET(13)] = read_gicreg(ICH_LR13_EL2);
+	case 12:
+		cpu_if->vgic_lr[LR_OFFSET(12)] = read_gicreg(ICH_LR12_EL2);
+	case 11:
+		cpu_if->vgic_lr[LR_OFFSET(11)] = read_gicreg(ICH_LR11_EL2);
+	case 10:
+		cpu_if->vgic_lr[LR_OFFSET(10)] = read_gicreg(ICH_LR10_EL2);
+	case 9:
+		cpu_if->vgic_lr[LR_OFFSET(9)] = read_gicreg(ICH_LR9_EL2);
+	case 8:
+		cpu_if->vgic_lr[LR_OFFSET(8)] = read_gicreg(ICH_LR8_EL2);
+	case 7:
+		cpu_if->vgic_lr[LR_OFFSET(7)] = read_gicreg(ICH_LR7_EL2);
+	case 6:
+		cpu_if->vgic_lr[LR_OFFSET(6)] = read_gicreg(ICH_LR6_EL2);
+	case 5:
+		cpu_if->vgic_lr[LR_OFFSET(5)] = read_gicreg(ICH_LR5_EL2);
+	case 4:
+		cpu_if->vgic_lr[LR_OFFSET(4)] = read_gicreg(ICH_LR4_EL2);
+	case 3:
+		cpu_if->vgic_lr[LR_OFFSET(3)] = read_gicreg(ICH_LR3_EL2);
+	case 2:
+		cpu_if->vgic_lr[LR_OFFSET(2)] = read_gicreg(ICH_LR2_EL2);
+	case 1:
+		cpu_if->vgic_lr[LR_OFFSET(1)] = read_gicreg(ICH_LR1_EL2);
+	case 0:
+		cpu_if->vgic_lr[LR_OFFSET(0)] = read_gicreg(ICH_LR0_EL2);
+	}
+
+	switch (nr_pri) {
+	case 7:
+		cpu_if->vgic_ap0r[3] = read_gicreg(ICH_AP0R3_EL2);
+		cpu_if->vgic_ap0r[2] = read_gicreg(ICH_AP0R2_EL2);
+	case 6:
+		cpu_if->vgic_ap0r[1] = read_gicreg(ICH_AP0R1_EL2);
+	default:
+		cpu_if->vgic_ap0r[0] = read_gicreg(ICH_AP0R0_EL2);
+	}
+
+	switch (nr_pri) {
+	case 7:
+		cpu_if->vgic_ap1r[3] = read_gicreg(ICH_AP1R3_EL2);
+		cpu_if->vgic_ap1r[2] = read_gicreg(ICH_AP1R2_EL2);
+	case 6:
+		cpu_if->vgic_ap1r[1] = read_gicreg(ICH_AP1R1_EL2);
+	default:
+		cpu_if->vgic_ap1r[0] = read_gicreg(ICH_AP1R0_EL2);
+	}
+
+	write_gicreg(read_gicreg(ICC_SRE_EL2) | ICC_SRE_EL2_ENABLE,
+		     ICC_SRE_EL2);
+	isb();
+	write_gicreg(1, ICC_SRE_EL1);
+}
+
+void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+	u64 val;
+	u32 nr_lr, nr_pri;
+
+	/* Make sure SRE is valid before writing the other registers */
+	write_gicreg(cpu_if->vgic_sre, ICC_SRE_EL1);
+	isb();
+
+	write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
+	write_gicreg(cpu_if->vgic_vmcr, ICH_VMCR_EL2);
+
+	val = read_gicreg(ICH_VTR_EL2);
+	nr_lr = val & 0xf;
+	nr_pri = ((u32)val >> 29) + 1;
+
+	switch (nr_pri) {
+	case 7:
+		 write_gicreg(cpu_if->vgic_ap1r[3], ICH_AP1R3_EL2);
+		 write_gicreg(cpu_if->vgic_ap1r[2], ICH_AP1R2_EL2);
+	case 6:	 	                           
+		 write_gicreg(cpu_if->vgic_ap1r[1], ICH_AP1R1_EL2);
+	default: 	       		    
+		 write_gicreg(cpu_if->vgic_ap1r[0], ICH_AP1R0_EL2);
+	}	 	                           
+		 	                           
+	switch (nr_pri) {
+	case 7:	 	                           
+		 write_gicreg(cpu_if->vgic_ap0r[3], ICH_AP0R3_EL2);
+		 write_gicreg(cpu_if->vgic_ap0r[2], ICH_AP0R2_EL2);
+	case 6:	 	                           
+		 write_gicreg(cpu_if->vgic_ap0r[1], ICH_AP0R1_EL2);
+	default: 	       		    
+		 write_gicreg(cpu_if->vgic_ap0r[0], ICH_AP0R0_EL2);
+	}
+
+	switch (nr_lr) {
+	case 15:
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(15)], ICH_LR15_EL2);
+	case 14:	      			      
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(14)], ICH_LR14_EL2);
+	case 13:	      			      
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(13)], ICH_LR13_EL2);
+	case 12:	      			      
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(12)], ICH_LR12_EL2);
+	case 11:	      			      
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(11)], ICH_LR11_EL2);
+	case 10:	      			      
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(10)], ICH_LR10_EL2);
+	case 9:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(9)], ICH_LR9_EL2);
+	case 8:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(8)], ICH_LR8_EL2);
+	case 7:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(7)], ICH_LR7_EL2);
+	case 6:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(6)], ICH_LR6_EL2);
+	case 5:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(5)], ICH_LR5_EL2);
+	case 4:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(4)], ICH_LR4_EL2);
+	case 3:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(3)], ICH_LR3_EL2);
+	case 2:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(2)], ICH_LR2_EL2);
+	case 1:		                                    
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(1)], ICH_LR1_EL2);
+	case 0:
+		write_gicreg(cpu_if->vgic_lr[LR_OFFSET(0)], ICH_LR0_EL2);
+	}
+
+	/*
+	 * Ensure that the above will have reached the
+	 * (re)distributors. This ensure the guest will read the
+	 * correct values from the memory-mapped interface.
+	 */
+	isb();
+	dsb(sy);
+
+	/*
+	 * Prevent the guest from touching the GIC system registers if
+	 * SRE isn't enabled for GICv3 emulation.
+	 */
+	if (!cpu_if->vgic_sre) {
+		write_gicreg(read_gicreg(ICC_SRE_EL2) & ~ICC_SRE_EL2_ENABLE,
+			     ICC_SRE_EL2);
+	}
+}
+
+u64 __hyp_text __vgic_v3_read_ich_vtr_el2(void)
+{
+	return read_gicreg(ICH_VTR_EL2);
+}
-- 
2.1.4




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