[PATCH 09/15] arm64: kvm: Split hyp/debug-sr.c to VHE/nVHE

David Brazdil
2020-04-30T14:49:09Z

This patch is part of a series which builds KVM's non-VHE hyp code separately
from VHE and the rest of the kernel.

debug-sr.c contains KVM's code for context-switching debug registers, with some
parts shared between VHE/nVHE. These common routines are moved to debug-sr.h,
VHE-specific code is left in debug-sr.c and nVHE-specific code is moved to
nvhe/debug-sr.c.

Functions are slightly refactored to move code hidden behind `has_vhe()` checks
to the corresponding .c file.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
arch/arm64/kernel/image-vars.h | 3 -
arch/arm64/kvm/hyp/debug-sr.c | 214 +----------------------------
arch/arm64/kvm/hyp/debug-sr.h | 167 ++++++++++++++++++++++
arch/arm64/kvm/hyp/nvhe/Makefile | 2 +-
arch/arm64/kvm/hyp/nvhe/debug-sr.c | 77 +++++++++++
5 files changed, 251 insertions(+), 212 deletions(-)
create mode 100644 arch/arm64/kvm/hyp/debug-sr.h
create mode 100644 arch/arm64/kvm/hyp/nvhe/debug-sr.c

diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index e2282a4304c5..0e9ede9c473a 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -61,15 +61,12 @@ __efistub__ctype = _ctype;
* memory mappings.
*/

-__hyp_text___debug_switch_to_guest = __debug_switch_to_guest;
-__hyp_text___debug_switch_to_host = __debug_switch_to_host;
__hyp_text___fpsimd_restore_state = __fpsimd_restore_state;
__hyp_text___fpsimd_save_state = __fpsimd_save_state;
__hyp_text___guest_enter = __guest_enter;
__hyp_text___guest_exit = __guest_exit;
__hyp_text___icache_flags = __icache_flags;
__hyp_text___kvm_enable_ssbs = __kvm_enable_ssbs;
-__hyp_text___kvm_get_mdcr_el2 = __kvm_get_mdcr_el2;
__hyp_text___kvm_handle_stub_hvc = __kvm_handle_stub_hvc;
__hyp_text___kvm_timer_set_cntvoff = __kvm_timer_set_cntvoff;
__hyp_text___sysreg32_restore_state = __sysreg32_restore_state;
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
index 0fc9872a1467..39e0b9bcc8b7 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c
@@ -4,221 +4,19 @@
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/

-#include <linux/compiler.h>
-#include <linux/kvm_host.h>
+#include "debug-sr.h"

-#include <asm/debug-monitors.h>
-#include <asm/kvm_asm.h>
-#include <asm/kvm_hyp.h>
-#include <asm/kvm_mmu.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); \
- /* Fall through */ \
- case 14: ptr[14] = read_debug(reg, 14); \
- /* Fall through */ \
- case 13: ptr[13] = read_debug(reg, 13); \
- /* Fall through */ \
- case 12: ptr[12] = read_debug(reg, 12); \
- /* Fall through */ \
- case 11: ptr[11] = read_debug(reg, 11); \
- /* Fall through */ \
- case 10: ptr[10] = read_debug(reg, 10); \
- /* Fall through */ \
- case 9: ptr[9] = read_debug(reg, 9); \
- /* Fall through */ \
- case 8: ptr[8] = read_debug(reg, 8); \
- /* Fall through */ \
- case 7: ptr[7] = read_debug(reg, 7); \
- /* Fall through */ \
- case 6: ptr[6] = read_debug(reg, 6); \
- /* Fall through */ \
- case 5: ptr[5] = read_debug(reg, 5); \
- /* Fall through */ \
- case 4: ptr[4] = read_debug(reg, 4); \
- /* Fall through */ \
- case 3: ptr[3] = read_debug(reg, 3); \
- /* Fall through */ \
- case 2: ptr[2] = read_debug(reg, 2); \
- /* Fall through */ \
- case 1: ptr[1] = read_debug(reg, 1); \
- /* Fall through */ \
- default: ptr[0] = read_debug(reg, 0); \
- }
-
-#define restore_debug(ptr,reg,nr) \
- switch (nr) { \
- case 15: write_debug(ptr[15], reg, 15); \
- /* Fall through */ \
- case 14: write_debug(ptr[14], reg, 14); \
- /* Fall through */ \
- case 13: write_debug(ptr[13], reg, 13); \
- /* Fall through */ \
- case 12: write_debug(ptr[12], reg, 12); \
- /* Fall through */ \
- case 11: write_debug(ptr[11], reg, 11); \
- /* Fall through */ \
- case 10: write_debug(ptr[10], reg, 10); \
- /* Fall through */ \
- case 9: write_debug(ptr[9], reg, 9); \
- /* Fall through */ \
- case 8: write_debug(ptr[8], reg, 8); \
- /* Fall through */ \
- case 7: write_debug(ptr[7], reg, 7); \
- /* Fall through */ \
- case 6: write_debug(ptr[6], reg, 6); \
- /* Fall through */ \
- case 5: write_debug(ptr[5], reg, 5); \
- /* Fall through */ \
- case 4: write_debug(ptr[4], reg, 4); \
- /* Fall through */ \
- case 3: write_debug(ptr[3], reg, 3); \
- /* Fall through */ \
- case 2: write_debug(ptr[2], reg, 2); \
- /* Fall through */ \
- case 1: write_debug(ptr[1], reg, 1); \
- /* Fall through */ \
- default: write_debug(ptr[0], reg, 0); \
- }
-
-static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
-{
- u64 reg;
-
- /* Clear pmscr in case of early return */
- *pmscr_el1 = 0;
-
- /* SPE present on this CPU? */
- if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
- ID_AA64DFR0_PMSVER_SHIFT))
- return;
-
- /* Yes; is it owned by EL3? */
- reg = read_sysreg_s(SYS_PMBIDR_EL1);
- if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
- return;
-
- /* No; is the host actually using the thing? */
- reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
- if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
- return;
-
- /* Yes; save the control register and disable data generation */
- *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
- write_sysreg_s(0, SYS_PMSCR_EL1);
- isb();
-
- /* Now drain all buffered data to memory */
- psb_csync();
- dsb(nsh);
-}
-
-static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
-{
- if (!pmscr_el1)
- return;
-
- /* The host page table is installed, but not yet synchronised */
- isb();
-
- /* Re-enable data generation */
- write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
-}
-
-static 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;
-
- 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);
-}
-
-static 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;
-
- 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_switch_to_guest(struct kvm_vcpu *vcpu)
+void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
{
- struct kvm_cpu_context *host_ctxt;
- struct kvm_cpu_context *guest_ctxt;
- struct kvm_guest_debug_arch *host_dbg;
- struct kvm_guest_debug_arch *guest_dbg;
-
- /*
- * Non-VHE: Disable and flush SPE data generation
- * VHE: The vcpu can run, but it can't hide.
- */
- if (!has_vhe())
- __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
-
- if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
- return;
-
- host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
- guest_ctxt = &vcpu->arch.ctxt;
- host_dbg = &vcpu->arch.host_debug_state.regs;
- guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
-
- __debug_save_state(vcpu, host_dbg, host_ctxt);
- __debug_restore_state(vcpu, guest_dbg, guest_ctxt);
+ __debug_switch_to_guest_common(vcpu);
}

-void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
+void __debug_switch_to_host(struct kvm_vcpu *vcpu)
{
- struct kvm_cpu_context *host_ctxt;
- struct kvm_cpu_context *guest_ctxt;
- struct kvm_guest_debug_arch *host_dbg;
- struct kvm_guest_debug_arch *guest_dbg;
-
- if (!has_vhe())
- __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
-
- if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
- return;
-
- host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
- guest_ctxt = &vcpu->arch.ctxt;
- host_dbg = &vcpu->arch.host_debug_state.regs;
- guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
-
- __debug_save_state(vcpu, guest_dbg, guest_ctxt);
- __debug_restore_state(vcpu, host_dbg, host_ctxt);
-
- vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
+ __debug_switch_to_host_common(vcpu);
}

-u32 __hyp_text __kvm_get_mdcr_el2(void)
+u32 __kvm_get_mdcr_el2(void)
{
return read_sysreg(mdcr_el2);
}
diff --git a/arch/arm64/kvm/hyp/debug-sr.h b/arch/arm64/kvm/hyp/debug-sr.h
new file mode 100644
index 000000000000..1e849f31cb74
--- /dev/null
+++ b/arch/arm64/kvm/hyp/debug-sr.h
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/debug-monitors.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.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); \
+ /* Fall through */ \
+ case 14: ptr[14] = read_debug(reg, 14); \
+ /* Fall through */ \
+ case 13: ptr[13] = read_debug(reg, 13); \
+ /* Fall through */ \
+ case 12: ptr[12] = read_debug(reg, 12); \
+ /* Fall through */ \
+ case 11: ptr[11] = read_debug(reg, 11); \
+ /* Fall through */ \
+ case 10: ptr[10] = read_debug(reg, 10); \
+ /* Fall through */ \
+ case 9: ptr[9] = read_debug(reg, 9); \
+ /* Fall through */ \
+ case 8: ptr[8] = read_debug(reg, 8); \
+ /* Fall through */ \
+ case 7: ptr[7] = read_debug(reg, 7); \
+ /* Fall through */ \
+ case 6: ptr[6] = read_debug(reg, 6); \
+ /* Fall through */ \
+ case 5: ptr[5] = read_debug(reg, 5); \
+ /* Fall through */ \
+ case 4: ptr[4] = read_debug(reg, 4); \
+ /* Fall through */ \
+ case 3: ptr[3] = read_debug(reg, 3); \
+ /* Fall through */ \
+ case 2: ptr[2] = read_debug(reg, 2); \
+ /* Fall through */ \
+ case 1: ptr[1] = read_debug(reg, 1); \
+ /* Fall through */ \
+ default: ptr[0] = read_debug(reg, 0); \
+ }
+
+#define restore_debug(ptr,reg,nr) \
+ switch (nr) { \
+ case 15: write_debug(ptr[15], reg, 15); \
+ /* Fall through */ \
+ case 14: write_debug(ptr[14], reg, 14); \
+ /* Fall through */ \
+ case 13: write_debug(ptr[13], reg, 13); \
+ /* Fall through */ \
+ case 12: write_debug(ptr[12], reg, 12); \
+ /* Fall through */ \
+ case 11: write_debug(ptr[11], reg, 11); \
+ /* Fall through */ \
+ case 10: write_debug(ptr[10], reg, 10); \
+ /* Fall through */ \
+ case 9: write_debug(ptr[9], reg, 9); \
+ /* Fall through */ \
+ case 8: write_debug(ptr[8], reg, 8); \
+ /* Fall through */ \
+ case 7: write_debug(ptr[7], reg, 7); \
+ /* Fall through */ \
+ case 6: write_debug(ptr[6], reg, 6); \
+ /* Fall through */ \
+ case 5: write_debug(ptr[5], reg, 5); \
+ /* Fall through */ \
+ case 4: write_debug(ptr[4], reg, 4); \
+ /* Fall through */ \
+ case 3: write_debug(ptr[3], reg, 3); \
+ /* Fall through */ \
+ case 2: write_debug(ptr[2], reg, 2); \
+ /* Fall through */ \
+ case 1: write_debug(ptr[1], reg, 1); \
+ /* Fall through */ \
+ default: write_debug(ptr[0], reg, 0); \
+ }
+
+static inline 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;
+
+ 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);
+}
+
+static inline 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;
+
+ 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);
+}
+
+static inline void __hyp_text
+__debug_switch_to_guest_common(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *host_ctxt;
+ struct kvm_cpu_context *guest_ctxt;
+ struct kvm_guest_debug_arch *host_dbg;
+ struct kvm_guest_debug_arch *guest_dbg;
+
+ if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
+ return;
+
+ host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ guest_ctxt = &vcpu->arch.ctxt;
+ host_dbg = &vcpu->arch.host_debug_state.regs;
+ guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
+
+ __debug_save_state(vcpu, host_dbg, host_ctxt);
+ __debug_restore_state(vcpu, guest_dbg, guest_ctxt);
+}
+
+static inline void __hyp_text
+__debug_switch_to_host_common(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpu_context *host_ctxt;
+ struct kvm_cpu_context *guest_ctxt;
+ struct kvm_guest_debug_arch *host_dbg;
+ struct kvm_guest_debug_arch *guest_dbg;
+
+ if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
+ return;
+
+ host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ guest_ctxt = &vcpu->arch.ctxt;
+ host_dbg = &vcpu->arch.host_debug_state.regs;
+ guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
+
+ __debug_save_state(vcpu, guest_dbg, guest_ctxt);
+ __debug_restore_state(vcpu, host_dbg, host_ctxt);
+
+ vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index 82fbd0b76501..bca3b862927c 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -7,7 +7,7 @@ asflags-y := -D__HYPERVISOR__
ccflags-y := -D__HYPERVISOR__ -fno-stack-protector -DDISABLE_BRANCH_PROFILING \
$(DISABLE_STACKLEAK_PLUGIN)

-obj-y := switch.o tlb.o host_hypercall.o ../hyp-entry.o
+obj-y := debug-sr.o switch.o tlb.o host_hypercall.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/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
new file mode 100644
index 000000000000..b3752cfdcf3d
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/debug-monitors.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+
+#include "../debug-sr.h"
+
+static void __hyp_text __debug_save_spe(u64 *pmscr_el1)
+{
+ u64 reg;
+
+ /* Clear pmscr in case of early return */
+ *pmscr_el1 = 0;
+
+ /* SPE present on this CPU? */
+ if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
+ ID_AA64DFR0_PMSVER_SHIFT))
+ return;
+
+ /* Yes; is it owned by EL3? */
+ reg = read_sysreg_s(SYS_PMBIDR_EL1);
+ if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
+ return;
+
+ /* No; is the host actually using the thing? */
+ reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
+ if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
+ return;
+
+ /* Yes; save the control register and disable data generation */
+ *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
+ write_sysreg_s(0, SYS_PMSCR_EL1);
+ isb();
+
+ /* Now drain all buffered data to memory */
+ psb_csync();
+ dsb(nsh);
+}
+
+static void __hyp_text __debug_restore_spe(u64 pmscr_el1)
+{
+ if (!pmscr_el1)
+ return;
+
+ /* The host page table is installed, but not yet synchronised */
+ isb();
+
+ /* Re-enable data generation */
+ write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
+}
+
+void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
+{
+ /* Disable and flush SPE data generation */
+ __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+ __debug_switch_to_guest_common(vcpu);
+}
+
+void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
+{
+ __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
+ __debug_switch_to_host_common(vcpu);
+}
+
+u32 __hyp_text __kvm_get_mdcr_el2(void)
+{
+ return read_sysreg(mdcr_el2);
+}
--
2.26.1