[PATCH v3 09/22] arm64: KVM: Implement debug save/restore
Marc Zyngier
marc.zyngier at arm.com
Mon Dec 7 02:53:25 PST 2015
Implement the debug save restore as a direct translation of
the assembly code version.
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Tested-by: Alex Bennée <alex.bennee at linaro.org>
Reviewed-by: Alex Bennée <alex.bennee at linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
---
arch/arm64/kvm/hyp/Makefile | 1 +
arch/arm64/kvm/hyp/debug-sr.c | 137 ++++++++++++++++++++++++++++++++++++++++++
arch/arm64/kvm/hyp/hyp.h | 9 +++
3 files changed, 147 insertions(+)
create mode 100644 arch/arm64/kvm/hyp/debug-sr.c
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index ec94200..ec14cac 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o
obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o
obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o
obj-$(CONFIG_KVM_ARM_HOST) += sysreg-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += debug-sr.o
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
new file mode 100644
index 0000000..7848322
--- /dev/null
+++ b/arch/arm64/kvm/hyp/debug-sr.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 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/kvm_host.h>
+
+#include <asm/kvm_mmu.h>
+
+#include "hyp.h"
+
+#define read_debug(r,n) read_sysreg(r##n##_el1)
+#define write_debug(v,r,n) write_sysreg(v, r##n##_el1)
+
+#define save_debug(ptr,reg,nr) \
+ switch (nr) { \
+ case 15: ptr[15] = read_debug(reg, 15); \
+ case 14: ptr[14] = read_debug(reg, 14); \
+ case 13: ptr[13] = read_debug(reg, 13); \
+ case 12: ptr[12] = read_debug(reg, 12); \
+ case 11: ptr[11] = read_debug(reg, 11); \
+ case 10: ptr[10] = read_debug(reg, 10); \
+ case 9: ptr[9] = read_debug(reg, 9); \
+ case 8: ptr[8] = read_debug(reg, 8); \
+ case 7: ptr[7] = read_debug(reg, 7); \
+ case 6: ptr[6] = read_debug(reg, 6); \
+ case 5: ptr[5] = read_debug(reg, 5); \
+ case 4: ptr[4] = read_debug(reg, 4); \
+ case 3: ptr[3] = read_debug(reg, 3); \
+ case 2: ptr[2] = read_debug(reg, 2); \
+ case 1: ptr[1] = read_debug(reg, 1); \
+ default: ptr[0] = read_debug(reg, 0); \
+ }
+
+#define restore_debug(ptr,reg,nr) \
+ switch (nr) { \
+ case 15: write_debug(ptr[15], reg, 15); \
+ case 14: write_debug(ptr[14], reg, 14); \
+ case 13: write_debug(ptr[13], reg, 13); \
+ case 12: write_debug(ptr[12], reg, 12); \
+ case 11: write_debug(ptr[11], reg, 11); \
+ case 10: write_debug(ptr[10], reg, 10); \
+ case 9: write_debug(ptr[9], reg, 9); \
+ case 8: write_debug(ptr[8], reg, 8); \
+ case 7: write_debug(ptr[7], reg, 7); \
+ case 6: write_debug(ptr[6], reg, 6); \
+ case 5: write_debug(ptr[5], reg, 5); \
+ case 4: write_debug(ptr[4], reg, 4); \
+ case 3: write_debug(ptr[3], reg, 3); \
+ case 2: write_debug(ptr[2], reg, 2); \
+ case 1: write_debug(ptr[1], reg, 1); \
+ default: write_debug(ptr[0], reg, 0); \
+ }
+
+void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
+ struct kvm_guest_debug_arch *dbg,
+ struct kvm_cpu_context *ctxt)
+{
+ u64 aa64dfr0;
+ int brps, wrps;
+
+ if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
+ return;
+
+ aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
+ brps = (aa64dfr0 >> 12) & 0xf;
+ wrps = (aa64dfr0 >> 20) & 0xf;
+
+ save_debug(dbg->dbg_bcr, dbgbcr, brps);
+ save_debug(dbg->dbg_bvr, dbgbvr, brps);
+ save_debug(dbg->dbg_wcr, dbgwcr, wrps);
+ save_debug(dbg->dbg_wvr, dbgwvr, wrps);
+
+ ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
+}
+
+void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
+ struct kvm_guest_debug_arch *dbg,
+ struct kvm_cpu_context *ctxt)
+{
+ u64 aa64dfr0;
+ int brps, wrps;
+
+ if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
+ return;
+
+ aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
+
+ brps = (aa64dfr0 >> 12) & 0xf;
+ wrps = (aa64dfr0 >> 20) & 0xf;
+
+ restore_debug(dbg->dbg_bcr, dbgbcr, brps);
+ restore_debug(dbg->dbg_bvr, dbgbvr, brps);
+ restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
+ restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
+
+ write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
+}
+
+void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu)
+{
+ /* If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY is set, perform
+ * a full save/restore cycle. */
+ if ((vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_KDE) ||
+ (vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_MDE))
+ vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
+
+ __debug_save_state(vcpu, &vcpu->arch.host_debug_state,
+ kern_hyp_va(vcpu->arch.host_cpu_context));
+}
+
+void __hyp_text __debug_cond_restore_host_state(struct kvm_vcpu *vcpu)
+{
+ __debug_restore_state(vcpu, &vcpu->arch.host_debug_state,
+ kern_hyp_va(vcpu->arch.host_cpu_context));
+
+ if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)
+ vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY;
+}
+
+u32 __hyp_text __debug_read_mdcr_el2(void)
+{
+ return read_sysreg(mdcr_el2);
+}
diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
index bffd308..454e46f 100644
--- a/arch/arm64/kvm/hyp/hyp.h
+++ b/arch/arm64/kvm/hyp/hyp.h
@@ -43,5 +43,14 @@ void __sysreg_restore_state(struct kvm_cpu_context *ctxt);
void __sysreg32_save_state(struct kvm_vcpu *vcpu);
void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
+void __debug_save_state(struct kvm_vcpu *vcpu,
+ struct kvm_guest_debug_arch *dbg,
+ struct kvm_cpu_context *ctxt);
+void __debug_restore_state(struct kvm_vcpu *vcpu,
+ struct kvm_guest_debug_arch *dbg,
+ struct kvm_cpu_context *ctxt);
+void __debug_cond_save_host_state(struct kvm_vcpu *vcpu);
+void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu);
+
#endif /* __ARM64_KVM_HYP_H__ */
--
2.1.4
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