[PATCH 23/56] KVM: arm64: Split hyp/sysreg-sr.c to VHE/nVHE
Marc Zyngier
maz at kernel.org
Wed Aug 5 13:56:27 EDT 2020
From: David Brazdil <dbrazdil at google.com>
sysreg-sr.c contains KVM's code for saving/restoring system registers, with
some code shared between VHE/nVHE. These common routines are moved to
a header file, VHE-specific code is moved to vhe/sysreg-sr.c and nVHE-specific
code to nvhe/sysreg-sr.c.
Signed-off-by: David Brazdil <dbrazdil at google.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-12-dbrazdil@google.com
---
arch/arm64/include/asm/kvm_host.h | 6 +-
arch/arm64/include/asm/kvm_hyp.h | 5 +-
arch/arm64/kernel/image-vars.h | 7 -
arch/arm64/kvm/arm.c | 8 +-
arch/arm64/kvm/hyp/Makefile | 4 +-
.../{sysreg-sr.c => include/hyp/sysreg-sr.h} | 158 ++----------------
arch/arm64/kvm/hyp/nvhe/Makefile | 2 +-
arch/arm64/kvm/hyp/nvhe/switch.c | 1 +
arch/arm64/kvm/hyp/nvhe/sysreg-sr.c | 46 +++++
arch/arm64/kvm/hyp/vhe/Makefile | 2 +-
arch/arm64/kvm/hyp/vhe/switch.c | 2 +-
arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 114 +++++++++++++
12 files changed, 191 insertions(+), 164 deletions(-)
rename arch/arm64/kvm/hyp/{sysreg-sr.c => include/hyp/sysreg-sr.h} (56%)
create mode 100644 arch/arm64/kvm/hyp/nvhe/sysreg-sr.c
create mode 100644 arch/arm64/kvm/hyp/vhe/sysreg-sr.c
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 49d1a5cd8f8f..e0920df1d0c1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -338,7 +338,7 @@ struct kvm_vcpu_arch {
struct vcpu_reset_state reset_state;
/* True when deferrable sysregs are loaded on the physical CPU,
- * see kvm_vcpu_load_sysregs and kvm_vcpu_put_sysregs. */
+ * see kvm_vcpu_load_sysregs_vhe and kvm_vcpu_put_sysregs_vhe. */
bool sysregs_loaded_on_cpu;
/* Guest PV state */
@@ -639,8 +639,8 @@ static inline int kvm_arm_have_ssbd(void)
}
}
-void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu);
-void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu);
+void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu);
+void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu);
int kvm_set_ipa_limit(void);
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 82fa05d15b8b..997c5bda1ac7 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -66,14 +66,15 @@ int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
void __timer_enable_traps(struct kvm_vcpu *vcpu);
void __timer_disable_traps(struct kvm_vcpu *vcpu);
+#ifdef __KVM_NVHE_HYPERVISOR__
void __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt);
void __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt);
+#else
void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt);
void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt);
void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt);
void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt);
-void __sysreg32_save_state(struct kvm_vcpu *vcpu);
-void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
+#endif
void __debug_switch_to_guest(struct kvm_vcpu *vcpu);
void __debug_switch_to_host(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index c44ca4e7dd66..59eb55893eaf 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -76,13 +76,6 @@ KVM_NVHE_ALIAS(abort_guest_exit_start);
KVM_NVHE_ALIAS(__fpsimd_restore_state);
KVM_NVHE_ALIAS(__fpsimd_save_state);
-/* Symbols defined in sysreg-sr.c (not yet compiled with nVHE build rules). */
-KVM_NVHE_ALIAS(__kvm_enable_ssbs);
-KVM_NVHE_ALIAS(__sysreg32_restore_state);
-KVM_NVHE_ALIAS(__sysreg32_save_state);
-KVM_NVHE_ALIAS(__sysreg_restore_state_nvhe);
-KVM_NVHE_ALIAS(__sysreg_save_state_nvhe);
-
/* Symbols defined in timer-sr.c (not yet compiled with nVHE build rules). */
KVM_NVHE_ALIAS(__kvm_timer_set_cntvoff);
KVM_NVHE_ALIAS(__timer_disable_traps);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 26780b78a523..0bf2cf5614c6 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -351,7 +351,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
kvm_vgic_load(vcpu);
kvm_timer_vcpu_load(vcpu);
- kvm_vcpu_load_sysregs(vcpu);
+ if (has_vhe())
+ kvm_vcpu_load_sysregs_vhe(vcpu);
kvm_arch_vcpu_load_fp(vcpu);
kvm_vcpu_pmu_restore_guest(vcpu);
if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
@@ -369,7 +370,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_arch_vcpu_put_fp(vcpu);
- kvm_vcpu_put_sysregs(vcpu);
+ if (has_vhe())
+ kvm_vcpu_put_sysregs_vhe(vcpu);
kvm_timer_vcpu_put(vcpu);
kvm_vgic_put(vcpu);
kvm_vcpu_pmu_restore_host(vcpu);
@@ -1302,7 +1304,7 @@ static void cpu_init_hyp_mode(void)
*/
if (this_cpu_has_cap(ARM64_SSBS) &&
arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
- kvm_call_hyp(__kvm_enable_ssbs);
+ kvm_call_hyp_nvhe(__kvm_enable_ssbs);
}
}
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index fc09025d2e97..f49797237818 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -13,8 +13,8 @@ subdir-ccflags-y := -I$(incdir) \
obj-$(CONFIG_KVM) += hyp.o vhe/ nvhe/
obj-$(CONFIG_KVM_INDIRECT_VECTORS) += smccc_wa.o
-hyp-y := vgic-v3-sr.o timer-sr.o aarch32.o vgic-v2-cpuif-proxy.o sysreg-sr.o \
- entry.o fpsimd.o
+hyp-y := vgic-v3-sr.o timer-sr.o aarch32.o vgic-v2-cpuif-proxy.o entry.o \
+ fpsimd.o
# KVM code is run at a different exception code with a different map, so
# compiler instrumentation that inserts callbacks or checks into the code may
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
similarity index 56%
rename from arch/arm64/kvm/hyp/sysreg-sr.c
rename to arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index 2493439a5c54..3e0585fbd403 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
@@ -4,6 +4,9 @@
* Author: Marc Zyngier <marc.zyngier at arm.com>
*/
+#ifndef __ARM64_KVM_HYP_SYSREG_SR_H__
+#define __ARM64_KVM_HYP_SYSREG_SR_H__
+
#include <linux/compiler.h>
#include <linux/kvm_host.h>
@@ -12,30 +15,18 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
-/*
- * Non-VHE: Both host and guest must save everything.
- *
- * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and
- * pstate, which are handled as part of the el2 return state) on every
- * switch (sp_el0 is being dealt with in the assembly code).
- * tpidr_el0 and tpidrro_el0 only need to be switched when going
- * to host userspace or a different VCPU. EL1 registers only need to be
- * switched when potentially going to run a different VCPU. The latter two
- * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put.
- */
-
-static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
}
-static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
}
-static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(SYS_SCTLR);
@@ -60,7 +51,7 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(SYS_SPSR);
}
-static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
{
ctxt->gp_regs.regs.pc = read_sysreg_el2(SYS_ELR);
ctxt->gp_regs.regs.pstate = read_sysreg_el2(SYS_SPSR);
@@ -69,39 +60,18 @@ static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ct
ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);
}
-void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt)
-{
- __sysreg_save_el1_state(ctxt);
- __sysreg_save_common_state(ctxt);
- __sysreg_save_user_state(ctxt);
- __sysreg_save_el2_return_state(ctxt);
-}
-
-void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
-{
- __sysreg_save_common_state(ctxt);
-}
-NOKPROBE_SYMBOL(sysreg_save_host_state_vhe);
-
-void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
-{
- __sysreg_save_common_state(ctxt);
- __sysreg_save_el2_return_state(ctxt);
-}
-NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
-
-static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
{
write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
}
-static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
{
write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
}
-static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
{
write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
@@ -160,8 +130,7 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],SYS_SPSR);
}
-static void __hyp_text
-__sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
+static inline void __hyp_text __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
{
u64 pstate = ctxt->gp_regs.regs.pstate;
u64 mode = pstate & PSR_AA32_MODE_MASK;
@@ -187,28 +156,7 @@ __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);
}
-void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
-{
- __sysreg_restore_el1_state(ctxt);
- __sysreg_restore_common_state(ctxt);
- __sysreg_restore_user_state(ctxt);
- __sysreg_restore_el2_return_state(ctxt);
-}
-
-void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
-{
- __sysreg_restore_common_state(ctxt);
-}
-NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe);
-
-void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
-{
- __sysreg_restore_common_state(ctxt);
- __sysreg_restore_el2_return_state(ctxt);
-}
-NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);
-
-void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
+static inline void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
{
u64 *spsr, *sysreg;
@@ -230,7 +178,7 @@ void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2);
}
-void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
+static inline void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
{
u64 *spsr, *sysreg;
@@ -252,82 +200,4 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2);
}
-/**
- * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU
- *
- * @vcpu: The VCPU pointer
- *
- * Load system registers that do not affect the host's execution, for
- * example EL1 system registers on a VHE system where the host kernel
- * runs at EL2. This function is called from KVM's vcpu_load() function
- * and loading system register state early avoids having to load them on
- * every entry to the VM.
- */
-void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
-{
- struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
- struct kvm_cpu_context *host_ctxt;
-
- if (!has_vhe())
- return;
-
- host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
- __sysreg_save_user_state(host_ctxt);
-
- /*
- * Load guest EL1 and user state
- *
- * We must restore the 32-bit state before the sysregs, thanks
- * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
- */
- __sysreg32_restore_state(vcpu);
- __sysreg_restore_user_state(guest_ctxt);
- __sysreg_restore_el1_state(guest_ctxt);
-
- vcpu->arch.sysregs_loaded_on_cpu = true;
-
- activate_traps_vhe_load(vcpu);
-}
-
-/**
- * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU
- *
- * @vcpu: The VCPU pointer
- *
- * Save guest system registers that do not affect the host's execution, for
- * example EL1 system registers on a VHE system where the host kernel
- * runs at EL2. This function is called from KVM's vcpu_put() function
- * and deferring saving system register state until we're no longer running the
- * VCPU avoids having to save them on every exit from the VM.
- */
-void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
-{
- struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
- struct kvm_cpu_context *host_ctxt;
-
- if (!has_vhe())
- return;
-
- host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
- deactivate_traps_vhe_put();
-
- __sysreg_save_el1_state(guest_ctxt);
- __sysreg_save_user_state(guest_ctxt);
- __sysreg32_save_state(vcpu);
-
- /* Restore host user state */
- __sysreg_restore_user_state(host_ctxt);
-
- vcpu->arch.sysregs_loaded_on_cpu = false;
-}
-
-void __hyp_text __kvm_enable_ssbs(void)
-{
- u64 tmp;
-
- asm volatile(
- "mrs %0, sctlr_el2\n"
- "orr %0, %0, %1\n"
- "msr sctlr_el2, %0"
- : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));
-}
+#endif /* __ARM64_KVM_HYP_SYSREG_SR_H__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index b3cb67b63d67..61a8160f0dd9 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -6,7 +6,7 @@
asflags-y := -D__KVM_NVHE_HYPERVISOR__
ccflags-y := -D__KVM_NVHE_HYPERVISOR__
-obj-y := debug-sr.o switch.o tlb.o hyp-init.o ../hyp-entry.o
+obj-y := sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o ../hyp-entry.o
obj-y := $(patsubst %.o,%.hyp.o,$(obj-y))
extra-y := $(patsubst %.hyp.o,%.hyp.tmp.o,$(obj-y))
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 7f6b8d3dc637..f08bfb951df6 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -5,6 +5,7 @@
*/
#include <hyp/switch.h>
+#include <hyp/sysreg-sr.h>
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
diff --git a/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c
new file mode 100644
index 000000000000..710cf28ab1ec
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier at arm.com>
+ */
+
+#include <hyp/sysreg-sr.h>
+
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kprobes.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+
+/*
+ * Non-VHE: Both host and guest must save everything.
+ */
+
+void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_el1_state(ctxt);
+ __sysreg_save_common_state(ctxt);
+ __sysreg_save_user_state(ctxt);
+ __sysreg_save_el2_return_state(ctxt);
+}
+
+void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_el1_state(ctxt);
+ __sysreg_restore_common_state(ctxt);
+ __sysreg_restore_user_state(ctxt);
+ __sysreg_restore_el2_return_state(ctxt);
+}
+
+void __hyp_text __kvm_enable_ssbs(void)
+{
+ u64 tmp;
+
+ asm volatile(
+ "mrs %0, sctlr_el2\n"
+ "orr %0, %0, %1\n"
+ "msr sctlr_el2, %0"
+ : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));
+}
diff --git a/arch/arm64/kvm/hyp/vhe/Makefile b/arch/arm64/kvm/hyp/vhe/Makefile
index 62bdaf272b03..2801582a739a 100644
--- a/arch/arm64/kvm/hyp/vhe/Makefile
+++ b/arch/arm64/kvm/hyp/vhe/Makefile
@@ -6,7 +6,7 @@
asflags-y := -D__KVM_VHE_HYPERVISOR__
ccflags-y := -D__KVM_VHE_HYPERVISOR__
-obj-y := debug-sr.o switch.o tlb.o ../hyp-entry.o
+obj-y := sysreg-sr.o debug-sr.o switch.o tlb.o ../hyp-entry.o
# KVM code is run at a different exception code with a different map, so
# compiler instrumentation that inserts callbacks or checks into the code may
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index e8d76cab44e4..c0d33deba77e 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -120,7 +120,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
* HCR_EL2.TGE.
*
* We have already configured the guest's stage 1 translation in
- * kvm_vcpu_load_sysregs above. We must now call __activate_vm
+ * kvm_vcpu_load_sysregs_vhe above. We must now call __activate_vm
* before __activate_traps, because __activate_vm configures
* stage 2 translation, and __activate_traps clear HCR_EL2.TGE
* (among other things).
diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
new file mode 100644
index 000000000000..996471e4c138
--- /dev/null
+++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier at arm.com>
+ */
+
+#include <hyp/sysreg-sr.h>
+
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kprobes.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+
+/*
+ * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and
+ * pstate, which are handled as part of the el2 return state) on every
+ * switch (sp_el0 is being dealt with in the assembly code).
+ * tpidr_el0 and tpidrro_el0 only need to be switched when going
+ * to host userspace or a different VCPU. EL1 registers only need to be
+ * switched when potentially going to run a different VCPU. The latter two
+ * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put.
+ */
+
+void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_common_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_save_host_state_vhe);
+
+void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_save_common_state(ctxt);
+ __sysreg_save_el2_return_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
+
+void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_common_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe);
+
+void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
+{
+ __sysreg_restore_common_state(ctxt);
+ __sysreg_restore_el2_return_state(ctxt);
+}
+NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);
+
+/**
+ * kvm_vcpu_load_sysregs_vhe - Load guest system registers to the physical CPU
+ *
+ * @vcpu: The VCPU pointer
+ *
+ * Load system registers that do not affect the host's execution, for
+ * example EL1 system registers on a VHE system where the host kernel
+ * runs at EL2. This function is called from KVM's vcpu_load() function
+ * and loading system register state early avoids having to load them on
+ * every entry to the VM.
+ */
+void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+ struct kvm_cpu_context *host_ctxt;
+
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
+ __sysreg_save_user_state(host_ctxt);
+
+ /*
+ * Load guest EL1 and user state
+ *
+ * We must restore the 32-bit state before the sysregs, thanks
+ * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
+ */
+ __sysreg32_restore_state(vcpu);
+ __sysreg_restore_user_state(guest_ctxt);
+ __sysreg_restore_el1_state(guest_ctxt);
+
+ vcpu->arch.sysregs_loaded_on_cpu = true;
+
+ activate_traps_vhe_load(vcpu);
+}
+
+/**
+ * kvm_vcpu_put_sysregs_vhe - Restore host system registers to the physical CPU
+ *
+ * @vcpu: The VCPU pointer
+ *
+ * Save guest system registers that do not affect the host's execution, for
+ * example EL1 system registers on a VHE system where the host kernel
+ * runs at EL2. This function is called from KVM's vcpu_put() function
+ * and deferring saving system register state until we're no longer running the
+ * VCPU avoids having to save them on every exit from the VM.
+ */
+void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
+ struct kvm_cpu_context *host_ctxt;
+
+ host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt;
+ deactivate_traps_vhe_put();
+
+ __sysreg_save_el1_state(guest_ctxt);
+ __sysreg_save_user_state(guest_ctxt);
+ __sysreg32_save_state(vcpu);
+
+ /* Restore host user state */
+ __sysreg_restore_user_state(host_ctxt);
+
+ vcpu->arch.sysregs_loaded_on_cpu = false;
+}
--
2.27.0
More information about the linux-arm-kernel
mailing list