From 1a6182033f2d5c481aec1f8c1c26ebc649693d57 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:41:54 -0700
Subject: [PATCH 1/9] KVM: arm64: selftests: Use FIELD_GET() to extract ID
 register fields

Use FIELD_GET() macro to extract ID register fields for existing
aarch64 selftests code. No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-2-reijiw@google.com
---
 tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c  | 3 ++-
 tools/testing/selftests/kvm/aarch64/debug-exceptions.c | 3 ++-
 tools/testing/selftests/kvm/lib/aarch64/processor.c    | 7 ++++---
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c b/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c
index 6f9c1f19c7f64..b6a5e8861b354 100644
--- a/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c
+++ b/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c
@@ -13,6 +13,7 @@
 #include "kvm_util.h"
 #include "processor.h"
 #include "test_util.h"
+#include <linux/bitfield.h>
 
 #define BAD_ID_REG_VAL	0x1badc0deul
 
@@ -145,7 +146,7 @@ static bool vcpu_aarch64_only(struct kvm_vcpu *vcpu)
 
 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), &val);
 
-	el0 = (val & ARM64_FEATURE_MASK(ID_AA64PFR0_EL0)) >> ID_AA64PFR0_EL0_SHIFT;
+	el0 = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL0), val);
 	return el0 == ID_AA64PFR0_ELx_64BIT_ONLY;
 }
 
diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 947bd201435ce..3808d3d750558 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -2,6 +2,7 @@
 #include <test_util.h>
 #include <kvm_util.h>
 #include <processor.h>
+#include <linux/bitfield.h>
 
 #define MDSCR_KDE	(1 << 13)
 #define MDSCR_MDE	(1 << 15)
@@ -284,7 +285,7 @@ static int debug_version(struct kvm_vcpu *vcpu)
 	uint64_t id_aa64dfr0;
 
 	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &id_aa64dfr0);
-	return id_aa64dfr0 & 0xf;
+	return FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), id_aa64dfr0);
 }
 
 static void test_guest_debug_exceptions(void)
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 6f5551368944e..7c96b931edd5c 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -11,6 +11,7 @@
 #include "guest_modes.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include <linux/bitfield.h>
 
 #define DEFAULT_ARM64_GUEST_STACK_VADDR_MIN	0xac0000
 
@@ -486,9 +487,9 @@ void aarch64_get_supported_page_sizes(uint32_t ipa,
 	err = ioctl(vcpu_fd, KVM_GET_ONE_REG, &reg);
 	TEST_ASSERT(err == 0, KVM_IOCTL_ERROR(KVM_GET_ONE_REG, vcpu_fd));
 
-	*ps4k = ((val >> 28) & 0xf) != 0xf;
-	*ps64k = ((val >> 24) & 0xf) == 0;
-	*ps16k = ((val >> 20) & 0xf) != 0;
+	*ps4k = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_TGRAN4), val) != 0xf;
+	*ps64k = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_TGRAN64), val) == 0;
+	*ps16k = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64MMFR0_TGRAN16), val) != 0;
 
 	close(vcpu_fd);
 	close(vm_fd);

From f6d02aa28ae21161d64300bac62b2dde85584004 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:41:55 -0700
Subject: [PATCH 2/9] KVM: arm64: selftests: Add write_dbg{b,w}{c,v}r helpers
 in debug-exceptions

Introduce helpers in the debug-exceptions test to write to
dbg{b,w}{c,v}r registers. Those helpers will be useful for
test cases that will be added to the test in subsequent patches.

No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-3-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 72 +++++++++++++++++--
 1 file changed, 68 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 3808d3d750558..d9884907fe87b 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -30,6 +30,69 @@ static volatile uint64_t svc_addr;
 static volatile uint64_t ss_addr[4], ss_idx;
 #define  PC(v)  ((uint64_t)&(v))
 
+#define GEN_DEBUG_WRITE_REG(reg_name)			\
+static void write_##reg_name(int num, uint64_t val)	\
+{							\
+	switch (num) {					\
+	case 0:						\
+		write_sysreg(val, reg_name##0_el1);	\
+		break;					\
+	case 1:						\
+		write_sysreg(val, reg_name##1_el1);	\
+		break;					\
+	case 2:						\
+		write_sysreg(val, reg_name##2_el1);	\
+		break;					\
+	case 3:						\
+		write_sysreg(val, reg_name##3_el1);	\
+		break;					\
+	case 4:						\
+		write_sysreg(val, reg_name##4_el1);	\
+		break;					\
+	case 5:						\
+		write_sysreg(val, reg_name##5_el1);	\
+		break;					\
+	case 6:						\
+		write_sysreg(val, reg_name##6_el1);	\
+		break;					\
+	case 7:						\
+		write_sysreg(val, reg_name##7_el1);	\
+		break;					\
+	case 8:						\
+		write_sysreg(val, reg_name##8_el1);	\
+		break;					\
+	case 9:						\
+		write_sysreg(val, reg_name##9_el1);	\
+		break;					\
+	case 10:					\
+		write_sysreg(val, reg_name##10_el1);	\
+		break;					\
+	case 11:					\
+		write_sysreg(val, reg_name##11_el1);	\
+		break;					\
+	case 12:					\
+		write_sysreg(val, reg_name##12_el1);	\
+		break;					\
+	case 13:					\
+		write_sysreg(val, reg_name##13_el1);	\
+		break;					\
+	case 14:					\
+		write_sysreg(val, reg_name##14_el1);	\
+		break;					\
+	case 15:					\
+		write_sysreg(val, reg_name##15_el1);	\
+		break;					\
+	default:					\
+		GUEST_ASSERT(0);			\
+	}						\
+}
+
+/* Define write_dbgbcr()/write_dbgbvr()/write_dbgwcr()/write_dbgwvr() */
+GEN_DEBUG_WRITE_REG(dbgbcr)
+GEN_DEBUG_WRITE_REG(dbgbvr)
+GEN_DEBUG_WRITE_REG(dbgwcr)
+GEN_DEBUG_WRITE_REG(dbgwvr)
+
 static void reset_debug_state(void)
 {
 	asm volatile("msr daifset, #8");
@@ -61,8 +124,9 @@ static void install_wp(uint64_t addr)
 	uint32_t mdscr;
 
 	wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E;
-	write_sysreg(wcr, dbgwcr0_el1);
-	write_sysreg(addr, dbgwvr0_el1);
+	write_dbgwcr(0, wcr);
+	write_dbgwvr(0, addr);
+
 	isb();
 
 	asm volatile("msr daifclr, #8");
@@ -78,8 +142,8 @@ static void install_hw_bp(uint64_t addr)
 	uint32_t mdscr;
 
 	bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E;
-	write_sysreg(bcr, dbgbcr0_el1);
-	write_sysreg(addr, dbgbvr0_el1);
+	write_dbgbcr(0, bcr);
+	write_dbgbvr(0, addr);
 	isb();
 
 	asm volatile("msr daifclr, #8");

From 700b8860e02cbaa7dd1181a914ff38e0fae18bf0 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:41:56 -0700
Subject: [PATCH 3/9] KVM: arm64: selftests: Remove the hard-coded {b,w}pn#0
 from debug-exceptions

Remove the hard-coded {break,watch}point #0 from the guest_code() in
debug-exceptions to allow {break,watch}point number to be specified.
Change reset_debug_state() to zeroing all dbg{b,w}{c,v}r_el0 registers
so that guest_code() can use the function to reset those registers
even when non-zero {break,watch}points are specified for guest_code().
Subsequent patches will add test cases for non-zero {break,watch}points.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-4-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 50 ++++++++++++-------
 1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index d9884907fe87b..608a6c8db9a21 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -95,6 +95,9 @@ GEN_DEBUG_WRITE_REG(dbgwvr)
 
 static void reset_debug_state(void)
 {
+	uint8_t brps, wrps, i;
+	uint64_t dfr0;
+
 	asm volatile("msr daifset, #8");
 
 	write_sysreg(0, osdlr_el1);
@@ -102,11 +105,20 @@ static void reset_debug_state(void)
 	isb();
 
 	write_sysreg(0, mdscr_el1);
-	/* This test only uses the first bp and wp slot. */
-	write_sysreg(0, dbgbvr0_el1);
-	write_sysreg(0, dbgbcr0_el1);
-	write_sysreg(0, dbgwcr0_el1);
-	write_sysreg(0, dbgwvr0_el1);
+
+	/* Reset all bcr/bvr/wcr/wvr registers */
+	dfr0 = read_sysreg(id_aa64dfr0_el1);
+	brps = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_BRPS), dfr0);
+	for (i = 0; i <= brps; i++) {
+		write_dbgbcr(i, 0);
+		write_dbgbvr(i, 0);
+	}
+	wrps = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_WRPS), dfr0);
+	for (i = 0; i <= wrps; i++) {
+		write_dbgwcr(i, 0);
+		write_dbgwvr(i, 0);
+	}
+
 	isb();
 }
 
@@ -118,14 +130,14 @@ static void enable_os_lock(void)
 	GUEST_ASSERT(read_sysreg(oslsr_el1) & 2);
 }
 
-static void install_wp(uint64_t addr)
+static void install_wp(uint8_t wpn, uint64_t addr)
 {
 	uint32_t wcr;
 	uint32_t mdscr;
 
 	wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E;
-	write_dbgwcr(0, wcr);
-	write_dbgwvr(0, addr);
+	write_dbgwcr(wpn, wcr);
+	write_dbgwvr(wpn, addr);
 
 	isb();
 
@@ -136,14 +148,14 @@ static void install_wp(uint64_t addr)
 	isb();
 }
 
-static void install_hw_bp(uint64_t addr)
+static void install_hw_bp(uint8_t bpn, uint64_t addr)
 {
 	uint32_t bcr;
 	uint32_t mdscr;
 
 	bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E;
-	write_dbgbcr(0, bcr);
-	write_dbgbvr(0, addr);
+	write_dbgbcr(bpn, bcr);
+	write_dbgbvr(bpn, addr);
 	isb();
 
 	asm volatile("msr daifclr, #8");
@@ -166,7 +178,7 @@ static void install_ss(void)
 
 static volatile char write_data;
 
-static void guest_code(void)
+static void guest_code(uint8_t bpn, uint8_t wpn)
 {
 	GUEST_SYNC(0);
 
@@ -179,7 +191,7 @@ static void guest_code(void)
 
 	/* Hardware-breakpoint */
 	reset_debug_state();
-	install_hw_bp(PC(hw_bp));
+	install_hw_bp(bpn, PC(hw_bp));
 	asm volatile("hw_bp: nop");
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp));
 
@@ -187,7 +199,7 @@ static void guest_code(void)
 
 	/* Hardware-breakpoint + svc */
 	reset_debug_state();
-	install_hw_bp(PC(bp_svc));
+	install_hw_bp(bpn, PC(bp_svc));
 	asm volatile("bp_svc: svc #0");
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_svc));
 	GUEST_ASSERT_EQ(svc_addr, PC(bp_svc) + 4);
@@ -196,7 +208,7 @@ static void guest_code(void)
 
 	/* Hardware-breakpoint + software-breakpoint */
 	reset_debug_state();
-	install_hw_bp(PC(bp_brk));
+	install_hw_bp(bpn, PC(bp_brk));
 	asm volatile("bp_brk: brk #0");
 	GUEST_ASSERT_EQ(sw_bp_addr, PC(bp_brk));
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_brk));
@@ -205,7 +217,7 @@ static void guest_code(void)
 
 	/* Watchpoint */
 	reset_debug_state();
-	install_wp(PC(write_data));
+	install_wp(wpn, PC(write_data));
 	write_data = 'x';
 	GUEST_ASSERT_EQ(write_data, 'x');
 	GUEST_ASSERT_EQ(wp_data_addr, PC(write_data));
@@ -239,7 +251,7 @@ static void guest_code(void)
 	/* OS Lock blocking hardware-breakpoint */
 	reset_debug_state();
 	enable_os_lock();
-	install_hw_bp(PC(hw_bp2));
+	install_hw_bp(bpn, PC(hw_bp2));
 	hw_bp_addr = 0;
 	asm volatile("hw_bp2: nop");
 	GUEST_ASSERT_EQ(hw_bp_addr, 0);
@@ -251,7 +263,7 @@ static void guest_code(void)
 	enable_os_lock();
 	write_data = '\0';
 	wp_data_addr = 0;
-	install_wp(PC(write_data));
+	install_wp(wpn, PC(write_data));
 	write_data = 'x';
 	GUEST_ASSERT_EQ(write_data, 'x');
 	GUEST_ASSERT_EQ(wp_data_addr, 0);
@@ -376,6 +388,8 @@ static void test_guest_debug_exceptions(void)
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_SVC64, guest_svc_handler);
 
+	/* Run tests with breakpoint#0 and watchpoint#0. */
+	vcpu_args_set(vcpu, 2, 0, 0);
 	for (stage = 0; stage < 11; stage++) {
 		vcpu_run(vcpu);
 

From 152880d8edf5ad6df5b4b4915a4d9f9085ab8fef Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:41:57 -0700
Subject: [PATCH 4/9] KVM: arm64: selftests: Add helpers to enable debug
 exceptions

Add helpers to enable breakpoint and watchpoint exceptions.
No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-5-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 25 ++++++++++---------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 608a6c8db9a21..0c237022f4d39 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -130,10 +130,20 @@ static void enable_os_lock(void)
 	GUEST_ASSERT(read_sysreg(oslsr_el1) & 2);
 }
 
+static void enable_monitor_debug_exceptions(void)
+{
+	uint32_t mdscr;
+
+	asm volatile("msr daifclr, #8");
+
+	mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_MDE;
+	write_sysreg(mdscr, mdscr_el1);
+	isb();
+}
+
 static void install_wp(uint8_t wpn, uint64_t addr)
 {
 	uint32_t wcr;
-	uint32_t mdscr;
 
 	wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E;
 	write_dbgwcr(wpn, wcr);
@@ -141,28 +151,19 @@ static void install_wp(uint8_t wpn, uint64_t addr)
 
 	isb();
 
-	asm volatile("msr daifclr, #8");
-
-	mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_MDE;
-	write_sysreg(mdscr, mdscr_el1);
-	isb();
+	enable_monitor_debug_exceptions();
 }
 
 static void install_hw_bp(uint8_t bpn, uint64_t addr)
 {
 	uint32_t bcr;
-	uint32_t mdscr;
 
 	bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E;
 	write_dbgbcr(bpn, bcr);
 	write_dbgbvr(bpn, addr);
 	isb();
 
-	asm volatile("msr daifclr, #8");
-
-	mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_MDE;
-	write_sysreg(mdscr, mdscr_el1);
-	isb();
+	enable_monitor_debug_exceptions();
 }
 
 static void install_ss(void)

From 948f439c9d0080972ec937f4aefbe51229546510 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:41:58 -0700
Subject: [PATCH 5/9] KVM: arm64: selftests: Stop unnecessary test stage
 tracking of debug-exceptions

Currently, debug-exceptions test unnecessarily tracks some test stages
using GUEST_SYNC().  The code for it needs to be updated as test cases
are added or removed.  Stop doing the unnecessary stage tracking,
as they are not so useful and are a bit pain to maintain.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-6-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 46 ++++---------------
 1 file changed, 9 insertions(+), 37 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 0c237022f4d39..040e4d7f8755c 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -181,23 +181,17 @@ static volatile char write_data;
 
 static void guest_code(uint8_t bpn, uint8_t wpn)
 {
-	GUEST_SYNC(0);
-
 	/* Software-breakpoint */
 	reset_debug_state();
 	asm volatile("sw_bp: brk #0");
 	GUEST_ASSERT_EQ(sw_bp_addr, PC(sw_bp));
 
-	GUEST_SYNC(1);
-
 	/* Hardware-breakpoint */
 	reset_debug_state();
 	install_hw_bp(bpn, PC(hw_bp));
 	asm volatile("hw_bp: nop");
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp));
 
-	GUEST_SYNC(2);
-
 	/* Hardware-breakpoint + svc */
 	reset_debug_state();
 	install_hw_bp(bpn, PC(bp_svc));
@@ -205,8 +199,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_svc));
 	GUEST_ASSERT_EQ(svc_addr, PC(bp_svc) + 4);
 
-	GUEST_SYNC(3);
-
 	/* Hardware-breakpoint + software-breakpoint */
 	reset_debug_state();
 	install_hw_bp(bpn, PC(bp_brk));
@@ -214,8 +206,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	GUEST_ASSERT_EQ(sw_bp_addr, PC(bp_brk));
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_brk));
 
-	GUEST_SYNC(4);
-
 	/* Watchpoint */
 	reset_debug_state();
 	install_wp(wpn, PC(write_data));
@@ -223,8 +213,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	GUEST_ASSERT_EQ(write_data, 'x');
 	GUEST_ASSERT_EQ(wp_data_addr, PC(write_data));
 
-	GUEST_SYNC(5);
-
 	/* Single-step */
 	reset_debug_state();
 	install_ss();
@@ -238,8 +226,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	GUEST_ASSERT_EQ(ss_addr[1], PC(ss_start) + 4);
 	GUEST_ASSERT_EQ(ss_addr[2], PC(ss_start) + 8);
 
-	GUEST_SYNC(6);
-
 	/* OS Lock does not block software-breakpoint */
 	reset_debug_state();
 	enable_os_lock();
@@ -247,8 +233,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	asm volatile("sw_bp2: brk #0");
 	GUEST_ASSERT_EQ(sw_bp_addr, PC(sw_bp2));
 
-	GUEST_SYNC(7);
-
 	/* OS Lock blocking hardware-breakpoint */
 	reset_debug_state();
 	enable_os_lock();
@@ -257,8 +241,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	asm volatile("hw_bp2: nop");
 	GUEST_ASSERT_EQ(hw_bp_addr, 0);
 
-	GUEST_SYNC(8);
-
 	/* OS Lock blocking watchpoint */
 	reset_debug_state();
 	enable_os_lock();
@@ -269,8 +251,6 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 	GUEST_ASSERT_EQ(write_data, 'x');
 	GUEST_ASSERT_EQ(wp_data_addr, 0);
 
-	GUEST_SYNC(9);
-
 	/* OS Lock blocking single-step */
 	reset_debug_state();
 	enable_os_lock();
@@ -370,7 +350,6 @@ static void test_guest_debug_exceptions(void)
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	struct ucall uc;
-	int stage;
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	ucall_init(vm, NULL);
@@ -391,23 +370,16 @@ static void test_guest_debug_exceptions(void)
 
 	/* Run tests with breakpoint#0 and watchpoint#0. */
 	vcpu_args_set(vcpu, 2, 0, 0);
-	for (stage = 0; stage < 11; stage++) {
-		vcpu_run(vcpu);
 
-		switch (get_ucall(vcpu, &uc)) {
-		case UCALL_SYNC:
-			TEST_ASSERT(uc.args[1] == stage,
-				"Stage %d: Unexpected sync ucall, got %lx",
-				stage, (ulong)uc.args[1]);
-			break;
-		case UCALL_ABORT:
-			REPORT_GUEST_ASSERT_2(uc, "values: %#lx, %#lx");
-			break;
-		case UCALL_DONE:
-			goto done;
-		default:
-			TEST_FAIL("Unknown ucall %lu", uc.cmd);
-		}
+	vcpu_run(vcpu);
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT_2(uc, "values: %#lx, %#lx");
+		break;
+	case UCALL_DONE:
+		goto done;
+	default:
+		TEST_FAIL("Unknown ucall %lu", uc.cmd);
 	}
 
 done:

From 5dd544e882d96d43b363c5ef64683281f2a386d9 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:41:59 -0700
Subject: [PATCH 6/9] KVM: arm64: selftests: Change debug_version() to take
 ID_AA64DFR0_EL1

Change debug_version() to take the ID_AA64DFR0_EL1 value instead of
vcpu as an argument, and change its callsite to read ID_AA64DFR0_EL1
(and pass it to debug_version()).
Subsequent patches will reuse the register value in the callsite.

No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-7-reijiw@google.com
---
 tools/testing/selftests/kvm/aarch64/debug-exceptions.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 040e4d7f8755c..72ec9bb166827 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -337,11 +337,8 @@ static void guest_code_ss(int test_cnt)
 	GUEST_DONE();
 }
 
-static int debug_version(struct kvm_vcpu *vcpu)
+static int debug_version(uint64_t id_aa64dfr0)
 {
-	uint64_t id_aa64dfr0;
-
-	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &id_aa64dfr0);
 	return FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), id_aa64dfr0);
 }
 
@@ -466,9 +463,11 @@ int main(int argc, char *argv[])
 	struct kvm_vm *vm;
 	int opt;
 	int ss_iteration = 10000;
+	uint64_t aa64dfr0;
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
-	__TEST_REQUIRE(debug_version(vcpu) >= 6,
+	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &aa64dfr0);
+	__TEST_REQUIRE(debug_version(aa64dfr0) >= 6,
 		       "Armv8 debug architecture not supported.");
 	kvm_vm_free(vm);
 

From 142365932f5f296df593dd653d79194ff5457722 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:42:00 -0700
Subject: [PATCH 7/9] KVM: arm64: selftests: Add a test case for a linked
 breakpoint

Currently, the debug-exceptions test doesn't have a test case for
a linked breakpoint. Add a test case for the linked breakpoint to
the test. The new test case uses a pair of breakpoints. One is the
higiest numbered context-aware breakpoint (for Context ID match),
and the other one is the breakpoint#0 (for Address Match), which
is linked to the context-aware breakpoint.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-8-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 63 +++++++++++++++++--
 1 file changed, 57 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 72ec9bb166827..362e7668a9782 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -12,6 +12,10 @@
 #define DBGBCR_EXEC	(0x0 << 3)
 #define DBGBCR_EL1	(0x1 << 1)
 #define DBGBCR_E	(0x1 << 0)
+#define DBGBCR_LBN_SHIFT	16
+#define DBGBCR_BT_SHIFT		20
+#define DBGBCR_BT_ADDR_LINK_CTX	(0x1 << DBGBCR_BT_SHIFT)
+#define DBGBCR_BT_CTX_LINK	(0x3 << DBGBCR_BT_SHIFT)
 
 #define DBGWCR_LEN8	(0xff << 5)
 #define DBGWCR_RD	(0x1 << 3)
@@ -22,7 +26,7 @@
 #define SPSR_D		(1 << 9)
 #define SPSR_SS		(1 << 21)
 
-extern unsigned char sw_bp, sw_bp2, hw_bp, hw_bp2, bp_svc, bp_brk, hw_wp, ss_start;
+extern unsigned char sw_bp, sw_bp2, hw_bp, hw_bp2, bp_svc, bp_brk, hw_wp, ss_start, hw_bp_ctx;
 extern unsigned char iter_ss_begin, iter_ss_end;
 static volatile uint64_t sw_bp_addr, hw_bp_addr;
 static volatile uint64_t wp_addr, wp_data_addr;
@@ -105,6 +109,7 @@ static void reset_debug_state(void)
 	isb();
 
 	write_sysreg(0, mdscr_el1);
+	write_sysreg(0, contextidr_el1);
 
 	/* Reset all bcr/bvr/wcr/wvr registers */
 	dfr0 = read_sysreg(id_aa64dfr0_el1);
@@ -166,6 +171,31 @@ static void install_hw_bp(uint8_t bpn, uint64_t addr)
 	enable_monitor_debug_exceptions();
 }
 
+void install_hw_bp_ctx(uint8_t addr_bp, uint8_t ctx_bp, uint64_t addr,
+		       uint64_t ctx)
+{
+	uint32_t addr_bcr, ctx_bcr;
+
+	/* Setup a context-aware breakpoint for Linked Context ID Match */
+	ctx_bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E |
+		  DBGBCR_BT_CTX_LINK;
+	write_dbgbcr(ctx_bp, ctx_bcr);
+	write_dbgbvr(ctx_bp, ctx);
+
+	/*
+	 * Setup a normal breakpoint for Linked Address Match, and link it
+	 * to the context-aware breakpoint.
+	 */
+	addr_bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E |
+		   DBGBCR_BT_ADDR_LINK_CTX |
+		   ((uint32_t)ctx_bp << DBGBCR_LBN_SHIFT);
+	write_dbgbcr(addr_bp, addr_bcr);
+	write_dbgbvr(addr_bp, addr);
+	isb();
+
+	enable_monitor_debug_exceptions();
+}
+
 static void install_ss(void)
 {
 	uint32_t mdscr;
@@ -179,8 +209,10 @@ static void install_ss(void)
 
 static volatile char write_data;
 
-static void guest_code(uint8_t bpn, uint8_t wpn)
+static void guest_code(uint8_t bpn, uint8_t wpn, uint8_t ctx_bpn)
 {
+	uint64_t ctx = 0xabcdef;	/* a random context number */
+
 	/* Software-breakpoint */
 	reset_debug_state();
 	asm volatile("sw_bp: brk #0");
@@ -263,6 +295,17 @@ static void guest_code(uint8_t bpn, uint8_t wpn)
 		     : : : "x0");
 	GUEST_ASSERT_EQ(ss_addr[0], 0);
 
+	/* Linked hardware-breakpoint */
+	hw_bp_addr = 0;
+	reset_debug_state();
+	install_hw_bp_ctx(bpn, ctx_bpn, PC(hw_bp_ctx), ctx);
+	/* Set context id */
+	write_sysreg(ctx, contextidr_el1);
+	isb();
+	asm volatile("hw_bp_ctx: nop");
+	write_sysreg(0, contextidr_el1);
+	GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp_ctx));
+
 	GUEST_DONE();
 }
 
@@ -342,11 +385,12 @@ static int debug_version(uint64_t id_aa64dfr0)
 	return FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), id_aa64dfr0);
 }
 
-static void test_guest_debug_exceptions(void)
+static void test_guest_debug_exceptions(uint64_t aa64dfr0)
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	struct ucall uc;
+	uint8_t brp_num;
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	ucall_init(vm, NULL);
@@ -365,8 +409,15 @@ static void test_guest_debug_exceptions(void)
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_SVC64, guest_svc_handler);
 
-	/* Run tests with breakpoint#0 and watchpoint#0. */
-	vcpu_args_set(vcpu, 2, 0, 0);
+	/* Number of breakpoints */
+	brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_BRPS), aa64dfr0) + 1;
+	__TEST_REQUIRE(brp_num >= 2, "At least two breakpoints are required");
+
+	/*
+	 * Run tests with breakpoint#0, watchpoint#0, and the higiest
+	 * numbered (context-aware) breakpoint.
+	 */
+	vcpu_args_set(vcpu, 3, 0, 0, brp_num - 1);
 
 	vcpu_run(vcpu);
 	switch (get_ucall(vcpu, &uc)) {
@@ -483,7 +534,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	test_guest_debug_exceptions();
+	test_guest_debug_exceptions(aa64dfr0);
 	test_single_step_from_userspace(ss_iteration);
 
 	return 0;

From 5ced4e533b676b1a582d89aba5328e4b316957e0 Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:42:01 -0700
Subject: [PATCH 8/9] KVM: arm64: selftests: Add a test case for a linked
 watchpoint

Currently, the debug-exceptions test doesn't have a test case for
a linked watchpoint. Add a test case for the linked watchpoint to
the test. The new test case uses the highest numbered context-aware
breakpoint (for Context ID match), and the watchpoint#0, which is
linked to the context-aware breakpoint.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-9-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 362e7668a9782..73a95e6b345e5 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -22,6 +22,9 @@
 #define DBGWCR_WR	(0x2 << 3)
 #define DBGWCR_EL1	(0x1 << 1)
 #define DBGWCR_E	(0x1 << 0)
+#define DBGWCR_LBN_SHIFT	16
+#define DBGWCR_WT_SHIFT		20
+#define DBGWCR_WT_LINK		(0x1 << DBGWCR_WT_SHIFT)
 
 #define SPSR_D		(1 << 9)
 #define SPSR_SS		(1 << 21)
@@ -171,6 +174,28 @@ static void install_hw_bp(uint8_t bpn, uint64_t addr)
 	enable_monitor_debug_exceptions();
 }
 
+static void install_wp_ctx(uint8_t addr_wp, uint8_t ctx_bp, uint64_t addr,
+			   uint64_t ctx)
+{
+	uint32_t wcr;
+	uint64_t ctx_bcr;
+
+	/* Setup a context-aware breakpoint for Linked Context ID Match */
+	ctx_bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E |
+		  DBGBCR_BT_CTX_LINK;
+	write_dbgbcr(ctx_bp, ctx_bcr);
+	write_dbgbvr(ctx_bp, ctx);
+
+	/* Setup a linked watchpoint (linked to the context-aware breakpoint) */
+	wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E |
+	      DBGWCR_WT_LINK | ((uint32_t)ctx_bp << DBGWCR_LBN_SHIFT);
+	write_dbgwcr(addr_wp, wcr);
+	write_dbgwvr(addr_wp, addr);
+	isb();
+
+	enable_monitor_debug_exceptions();
+}
+
 void install_hw_bp_ctx(uint8_t addr_bp, uint8_t ctx_bp, uint64_t addr,
 		       uint64_t ctx)
 {
@@ -306,6 +331,16 @@ static void guest_code(uint8_t bpn, uint8_t wpn, uint8_t ctx_bpn)
 	write_sysreg(0, contextidr_el1);
 	GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp_ctx));
 
+	/* Linked watchpoint */
+	reset_debug_state();
+	install_wp_ctx(wpn, ctx_bpn, PC(write_data), ctx);
+	/* Set context id */
+	write_sysreg(ctx, contextidr_el1);
+	isb();
+	write_data = 'x';
+	GUEST_ASSERT_EQ(write_data, 'x');
+	GUEST_ASSERT_EQ(wp_data_addr, PC(write_data));
+
 	GUEST_DONE();
 }
 

From ebb8cc10316de3040efc4cfb40030f374cbbaa3b Mon Sep 17 00:00:00 2001
From: Reiji Watanabe <reijiw@google.com>
Date: Wed, 19 Oct 2022 22:42:02 -0700
Subject: [PATCH 9/9] KVM: arm64: selftests: Test with every
 breakpoint/watchpoint

Currently, the debug-exceptions test always uses only
{break,watch}point#0 and the highest numbered context-aware
breakpoint. Modify the test to use all {break,watch}points and
context-aware breakpoints supported on the system.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-10-reijiw@google.com
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 54 ++++++++++++++-----
 1 file changed, 42 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 73a95e6b345e5..b30add3e77269 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -420,12 +420,11 @@ static int debug_version(uint64_t id_aa64dfr0)
 	return FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_DEBUGVER), id_aa64dfr0);
 }
 
-static void test_guest_debug_exceptions(uint64_t aa64dfr0)
+static void test_guest_debug_exceptions(uint8_t bpn, uint8_t wpn, uint8_t ctx_bpn)
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	struct ucall uc;
-	uint8_t brp_num;
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	ucall_init(vm, NULL);
@@ -444,15 +443,9 @@ static void test_guest_debug_exceptions(uint64_t aa64dfr0)
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_SVC64, guest_svc_handler);
 
-	/* Number of breakpoints */
-	brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_BRPS), aa64dfr0) + 1;
-	__TEST_REQUIRE(brp_num >= 2, "At least two breakpoints are required");
-
-	/*
-	 * Run tests with breakpoint#0, watchpoint#0, and the higiest
-	 * numbered (context-aware) breakpoint.
-	 */
-	vcpu_args_set(vcpu, 3, 0, 0, brp_num - 1);
+	/* Specify bpn/wpn/ctx_bpn to be tested */
+	vcpu_args_set(vcpu, 3, bpn, wpn, ctx_bpn);
+	pr_debug("Use bpn#%d, wpn#%d and ctx_bpn#%d\n", bpn, wpn, ctx_bpn);
 
 	vcpu_run(vcpu);
 	switch (get_ucall(vcpu, &uc)) {
@@ -535,6 +528,43 @@ void test_single_step_from_userspace(int test_cnt)
 	kvm_vm_free(vm);
 }
 
+/*
+ * Run debug testing using the various breakpoint#, watchpoint# and
+ * context-aware breakpoint# with the given ID_AA64DFR0_EL1 configuration.
+ */
+void test_guest_debug_exceptions_all(uint64_t aa64dfr0)
+{
+	uint8_t brp_num, wrp_num, ctx_brp_num, normal_brp_num, ctx_brp_base;
+	int b, w, c;
+
+	/* Number of breakpoints */
+	brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_BRPS), aa64dfr0) + 1;
+	__TEST_REQUIRE(brp_num >= 2, "At least two breakpoints are required");
+
+	/* Number of watchpoints */
+	wrp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_WRPS), aa64dfr0) + 1;
+
+	/* Number of context aware breakpoints */
+	ctx_brp_num = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_CTX_CMPS), aa64dfr0) + 1;
+
+	pr_debug("%s brp_num:%d, wrp_num:%d, ctx_brp_num:%d\n", __func__,
+		 brp_num, wrp_num, ctx_brp_num);
+
+	/* Number of normal (non-context aware) breakpoints */
+	normal_brp_num = brp_num - ctx_brp_num;
+
+	/* Lowest context aware breakpoint number */
+	ctx_brp_base = normal_brp_num;
+
+	/* Run tests with all supported breakpoints/watchpoints */
+	for (c = ctx_brp_base; c < ctx_brp_base + ctx_brp_num; c++) {
+		for (b = 0; b < normal_brp_num; b++) {
+			for (w = 0; w < wrp_num; w++)
+				test_guest_debug_exceptions(b, w, c);
+		}
+	}
+}
+
 static void help(char *name)
 {
 	puts("");
@@ -569,7 +599,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	test_guest_debug_exceptions(aa64dfr0);
+	test_guest_debug_exceptions_all(aa64dfr0);
 	test_single_step_from_userspace(ss_iteration);
 
 	return 0;