In an effort to remove the vcpu PC manipulations from EL1 on nVHE
systems, move kvm_skip_instr() to be HYP-specific. EL1's intent
to increment PC post emulation is now signalled via a flag in the
vcpu structure.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_emulate.h | 27 +----------
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/handle_exit.c | 6 +--
arch/arm64/kvm/hyp/include/hyp/adjust_pc.h | 56 ++++++++++++++++++++++
arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +
arch/arm64/kvm/hyp/nvhe/switch.c | 3 ++
arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c | 2 +
arch/arm64/kvm/hyp/vgic-v3-sr.c | 2 +
arch/arm64/kvm/hyp/vhe/switch.c | 3 ++
arch/arm64/kvm/mmio.c | 2 +-
arch/arm64/kvm/mmu.c | 2 +-
arch/arm64/kvm/sys_regs.c | 2 +-
12 files changed, 77 insertions(+), 31 deletions(-)
create mode 100644 arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 0864f425547d..6d2b5d1aa7b3 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -472,32 +472,9 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
return data; /* Leave LE untouched */
}
-static __always_inline void kvm_skip_instr(struct kvm_vcpu *vcpu)
+static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
{
- if (vcpu_mode_is_32bit(vcpu)) {
- kvm_skip_instr32(vcpu);
- } else {
- *vcpu_pc(vcpu) += 4;
- *vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;
- }
-
- /* advance the singlestep state machine */
- *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
-}
-
-/*
- * Skip an instruction which has been emulated at hyp while most guest sysregs
- * are live.
- */
-static __always_inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)
-{
- *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
- vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);
-
- kvm_skip_instr(vcpu);
-
- write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);
- write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
+ vcpu->arch.flags |= KVM_ARM64_INCREMENT_PC;
}
#endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 0aecbab6a7fb..9a75de3ad8da 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -406,6 +406,7 @@ struct kvm_vcpu_arch {
#define KVM_ARM64_GUEST_HAS_SVE (1 << 5) /* SVE exposed to guest */
#define KVM_ARM64_VCPU_SVE_FINALIZED (1 << 6) /* SVE config completed */
#define KVM_ARM64_GUEST_HAS_PTRAUTH (1 << 7) /* PTRAUTH exposed to guest */
+#define KVM_ARM64_INCREMENT_PC (1 << 8) /* Increment PC */
#define vcpu_has_sve(vcpu) (system_supports_sve() && \
((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 30bf8e22df54..d4e00a864ee6 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -61,7 +61,7 @@ static int handle_smc(struct kvm_vcpu *vcpu)
* otherwise return to the same address...
*/
vcpu_set_reg(vcpu, 0, ~0UL);
- kvm_skip_instr(vcpu);
+ kvm_incr_pc(vcpu);
return 1;
}
@@ -100,7 +100,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu)
kvm_clear_request(KVM_REQ_UNHALT, vcpu);
}
- kvm_skip_instr(vcpu);
+ kvm_incr_pc(vcpu);
return 1;
}
@@ -221,7 +221,7 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu)
* that fail their condition code check"
*/
if (!kvm_condition_valid(vcpu)) {
- kvm_skip_instr(vcpu);
+ kvm_incr_pc(vcpu);
handled = 1;
} else {
exit_handle_fn exit_handler;
diff --git a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
new file mode 100644
index 000000000000..4ecaf5cb2633
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Guest PC manipulation helpers
+ *
+ * Copyright (C) 2012,2013 - ARM Ltd
+ * Copyright (C) 2020 - Google LLC
+ * Author: Marc Zyngier <maz@xxxxxxxxxx>
+ */
+
+#ifndef __ARM64_KVM_HYP_ADJUST_PC_H__
+#define __ARM64_KVM_HYP_ADJUST_PC_H__
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_host.h>
+
+static inline void kvm_skip_instr(struct kvm_vcpu *vcpu)
+{
+ if (vcpu_mode_is_32bit(vcpu)) {
+ kvm_skip_instr32(vcpu);
+ } else {
+ *vcpu_pc(vcpu) += 4;
+ *vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;
+ }
+
+ /* advance the singlestep state machine */
+ *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
+}
+
+/*
+ * Skip an instruction which has been emulated at hyp while most guest sysregs
+ * are live.
+ */
+static inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)
+{
+ *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
+ vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);
+
+ __kvm_skip_instr(vcpu);
+
+ write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);
+ write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
+}
+
+/*
+ * Adjust the guest PC on entry, depending on flags provided by EL1
+ * for the purpose of emulation (MMIO, sysreg).
+ */
+static inline void __adjust_pc(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.flags & KVM_ARM64_INCREMENT_PC) {
+ kvm_skip_instr(vcpu);
+ vcpu->arch.flags &= ~KVM_ARM64_INCREMENT_PC;
+ }
+}
+
+#endif
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 313a8fa3c721..d687e574cde5 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -7,6 +7,8 @@
#ifndef __ARM64_KVM_HYP_SWITCH_H__
#define __ARM64_KVM_HYP_SWITCH_H__
+#include <hyp/adjust_pc.h>
+
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/types.h>
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index a457a0306e03..d918861e040b 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -4,6 +4,7 @@
* Author: Marc Zyngier <marc.zyngier@xxxxxxx>
*/
+#include <hyp/adjust_pc.h>
#include <hyp/switch.h>
#include <hyp/sysreg-sr.h>
@@ -189,6 +190,8 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
__sysreg_save_state_nvhe(host_ctxt);
+ __adjust_pc(vcpu);
+
/*
* We must restore the 32-bit state before the sysregs, thanks
* to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
diff --git a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
index bd1bab551d48..8f0585640241 100644
--- a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
+++ b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
@@ -4,6 +4,8 @@
* Author: Marc Zyngier <marc.zyngier@xxxxxxx>
*/
+#include <hyp/adjust_pc.h>
+
#include <linux/compiler.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm_host.h>
diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 452f4cacd674..80406f463c28 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -4,6 +4,8 @@
* Author: Marc Zyngier <marc.zyngier@xxxxxxx>
*/
+#include <hyp/adjust_pc.h>
+
#include <linux/compiler.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/kvm_host.h>
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index fe69de16dadc..2adfda918be2 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -4,6 +4,7 @@
* Author: Marc Zyngier <marc.zyngier@xxxxxxx>
*/
+#include <hyp/adjust_pc.h>
#include <hyp/switch.h>
#include <linux/arm-smccc.h>
@@ -133,6 +134,8 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
__load_guest_stage2(vcpu->arch.hw_mmu);
__activate_traps(vcpu);
+ __adjust_pc(vcpu);
+
sysreg_restore_guest_state_vhe(guest_ctxt);
__debug_switch_to_guest(vcpu);
diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
index 7e8eb32ae7d2..3e2d8ba11a02 100644
--- a/arch/arm64/kvm/mmio.c
+++ b/arch/arm64/kvm/mmio.c
@@ -115,7 +115,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
* The MMIO instruction is emulated and should not be re-executed
* in the guest.
*/
- kvm_skip_instr(vcpu);
+ kvm_incr_pc(vcpu);
return 0;
}
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 080917c3f960..cc323d96c9d4 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1001,7 +1001,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
* cautious, and skip the instruction.
*/
if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) {
- kvm_skip_instr(vcpu);
+ kvm_incr_pc(vcpu);
ret = 1;
goto out_unlock;
}
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 894e800d6c61..01f63027cf40 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2199,7 +2199,7 @@ static void perform_access(struct kvm_vcpu *vcpu,
/* Skip instruction if instructed so */
if (likely(r->access(vcpu, params, r)))
- kvm_skip_instr(vcpu);
+ kvm_incr_pc(vcpu);
}
/*
--
2.28.0
