From: Chao Du <duchao@eswincomputing.com>
To: qemu-devel@nongnu.org, qemu-riscv@nongnu.org,
pbonzini@redhat.com, alistair23@gmail.com,
bin.meng@windriver.com, liweiwei@iscas.ac.cn,
dbarboza@ventanamicro.com, zhiwei_liu@linux.alibaba.com,
palmer@dabbelt.com, anup@brainfault.org, atishp@atishpatra.org
Subject: [RFC PATCH 1/4] target/riscv/kvm: add software breakpoints support
Date: Thu, 21 Dec 2023 09:49:20 +0000 [thread overview]
Message-ID: <20231221094923.7349-2-duchao@eswincomputing.com> (raw)
In-Reply-To: <20231221094923.7349-1-duchao@eswincomputing.com>
This patch implements insert/remove software breakpoint process:
Add an input parameter for kvm_arch_insert_sw_breakpoint() and
kvm_arch_remove_sw_breakpoint() to pass the length information,
which helps us to know whether it is a compressed instruction.
For some remove cases, we do not have the length info, so we need
to judge by ourselves.
For RISC-V, GDB treats single-step similarly to breakpoint: add a
breakpoint at the next step address, then continue. So this also
works for single-step debugging.
Add some stubs which are necessary for building, and will be
implemented later.
Signed-off-by: Chao Du <duchao@eswincomputing.com>
---
accel/kvm/kvm-all.c | 8 ++--
include/sysemu/kvm.h | 6 ++-
target/arm/kvm64.c | 6 ++-
target/i386/kvm/kvm.c | 6 ++-
target/mips/kvm.c | 6 ++-
target/ppc/kvm.c | 6 ++-
target/riscv/kvm/kvm-cpu.c | 79 ++++++++++++++++++++++++++++++++++++++
target/s390x/kvm/kvm.c | 6 ++-
8 files changed, 107 insertions(+), 16 deletions(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index e39a810a4e..ccc505d0c2 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -3231,7 +3231,7 @@ int kvm_insert_breakpoint(CPUState *cpu, int type, vaddr addr, vaddr len)
bp = g_new(struct kvm_sw_breakpoint, 1);
bp->pc = addr;
bp->use_count = 1;
- err = kvm_arch_insert_sw_breakpoint(cpu, bp);
+ err = kvm_arch_insert_sw_breakpoint(cpu, bp, len);
if (err) {
g_free(bp);
return err;
@@ -3270,7 +3270,7 @@ int kvm_remove_breakpoint(CPUState *cpu, int type, vaddr addr, vaddr len)
return 0;
}
- err = kvm_arch_remove_sw_breakpoint(cpu, bp);
+ err = kvm_arch_remove_sw_breakpoint(cpu, bp, len);
if (err) {
return err;
}
@@ -3300,10 +3300,10 @@ void kvm_remove_all_breakpoints(CPUState *cpu)
CPUState *tmpcpu;
QTAILQ_FOREACH_SAFE(bp, &s->kvm_sw_breakpoints, entry, next) {
- if (kvm_arch_remove_sw_breakpoint(cpu, bp) != 0) {
+ if (kvm_arch_remove_sw_breakpoint(cpu, bp, 0) != 0) {
/* Try harder to find a CPU that currently sees the breakpoint. */
CPU_FOREACH(tmpcpu) {
- if (kvm_arch_remove_sw_breakpoint(tmpcpu, bp) == 0) {
+ if (kvm_arch_remove_sw_breakpoint(tmpcpu, bp, 0) == 0) {
break;
}
}
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index d614878164..ab38c23def 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -391,9 +391,11 @@ struct kvm_sw_breakpoint *kvm_find_sw_breakpoint(CPUState *cpu,
int kvm_sw_breakpoints_active(CPUState *cpu);
int kvm_arch_insert_sw_breakpoint(CPUState *cpu,
- struct kvm_sw_breakpoint *bp);
+ struct kvm_sw_breakpoint *bp,
+ vaddr len);
int kvm_arch_remove_sw_breakpoint(CPUState *cpu,
- struct kvm_sw_breakpoint *bp);
+ struct kvm_sw_breakpoint *bp,
+ vaddr len);
int kvm_arch_insert_hw_breakpoint(vaddr addr, vaddr len, int type);
int kvm_arch_remove_hw_breakpoint(vaddr addr, vaddr len, int type);
void kvm_arch_remove_all_hw_breakpoints(void);
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 3c175c93a7..023e92b577 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -1139,7 +1139,8 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
/* C6.6.29 BRK instruction */
static const uint32_t brk_insn = 0xd4200000;
-int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
if (have_guest_debug) {
if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
@@ -1153,7 +1154,8 @@ int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
}
}
-int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
static uint32_t brk;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 4ce80555b4..742b7c8296 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -4935,7 +4935,8 @@ static int kvm_handle_tpr_access(X86CPU *cpu)
return 1;
}
-int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
static const uint8_t int3 = 0xcc;
@@ -4946,7 +4947,8 @@ int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
return 0;
}
-int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
uint8_t int3;
diff --git a/target/mips/kvm.c b/target/mips/kvm.c
index e22e24ed97..2f68938cdf 100644
--- a/target/mips/kvm.c
+++ b/target/mips/kvm.c
@@ -112,13 +112,15 @@ void kvm_mips_reset_vcpu(MIPSCPU *cpu)
DPRINTF("%s\n", __func__);
}
-int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
DPRINTF("%s\n", __func__);
return 0;
}
-int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
DPRINTF("%s\n", __func__);
return 0;
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 9b1abe2fc4..a99c85b2f3 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -1375,7 +1375,8 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env,
return 0;
}
-int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
/* Mixed endian case is not handled */
uint32_t sc = debug_inst_opcode;
@@ -1389,7 +1390,8 @@ int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
return 0;
}
-int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
uint32_t sc;
diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
index 45b6cf1cfa..e9110006b0 100644
--- a/target/riscv/kvm/kvm-cpu.c
+++ b/target/riscv/kvm/kvm-cpu.c
@@ -1521,3 +1521,82 @@ static const TypeInfo riscv_kvm_cpu_type_infos[] = {
};
DEFINE_TYPES(riscv_kvm_cpu_type_infos)
+
+static const uint32_t ebreak_insn = 0x00100073;
+static const uint16_t c_ebreak_insn = 0x9002;
+
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
+{
+ if (len != 4 && len != 2) {
+ return -EINVAL;
+ }
+
+ uint8_t * insn = (len == 4) ? (uint8_t *)&ebreak_insn :
+ (uint8_t *)&c_ebreak_insn;
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, len, 0) ||
+ cpu_memory_rw_debug(cs, bp->pc, insn, len, 1)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
+{
+ uint8_t length;
+
+ if (len == 4 || len == 2) {
+ length = (uint8_t)len;
+ } else if (len == 0) {
+ /* Need to decide the instruction length in this case. */
+ uint32_t read_4_bytes;
+ uint16_t read_2_bytes;
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&read_4_bytes, 4, 0) ||
+ cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&read_2_bytes, 2, 0)) {
+ return -EINVAL;
+ }
+
+ if (read_4_bytes == ebreak_insn) {
+ length = 4;
+ } else if (read_2_bytes == c_ebreak_insn) {
+ length = 2;
+ } else {
+ return -EINVAL;
+ }
+ } else {
+ return -EINVAL;
+ }
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn,
+ length, 1)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int kvm_arch_insert_hw_breakpoint(vaddr addr, vaddr len, int type)
+{
+ /* TODO; To be implemented later. */
+ return -EINVAL;
+}
+
+int kvm_arch_remove_hw_breakpoint(vaddr addr, vaddr len, int type)
+{
+ /* TODO; To be implemented later. */
+ return -EINVAL;
+}
+
+void kvm_arch_remove_all_hw_breakpoints(void)
+{
+ /* TODO; To be implemented later. */
+}
+
+void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
+{
+ /* TODO; To be implemented later. */
+}
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 33ab3551f4..fafacedd6a 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -867,7 +867,8 @@ static void determine_sw_breakpoint_instr(void)
}
}
-int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
determine_sw_breakpoint_instr();
@@ -879,7 +880,8 @@ int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
return 0;
}
-int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp,
+ vaddr len)
{
uint8_t t[MAX_ILEN];
--
2.17.1
next prev parent reply other threads:[~2023-12-21 9:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 9:49 [RFC PATCH 0/4] target/riscv/kvm: QEMU support for KVM Guest Debug on RISC-V Chao Du
2023-12-21 9:49 ` Chao Du [this message]
2024-04-16 9:23 ` [RFC PATCH 1/4] target/riscv/kvm: add software breakpoints support Daniel Henrique Barboza
2024-04-18 9:46 ` Chao Du
2024-05-24 16:11 ` Paolo Bonzini
2024-05-27 2:12 ` Chao Du
2023-12-21 9:49 ` [RFC PATCH 2/4] target/riscv/kvm: implement kvm_arch_update_guest_debug() Chao Du
2023-12-21 9:49 ` [RFC PATCH 3/4] target/riscv/kvm: handle the exit with debug reason Chao Du
2023-12-21 9:49 ` [RFC PATCH 4/4] linux-headers: enable KVM GUEST DEBUG for RISC-V Chao Du
2023-12-22 14:16 ` [RFC PATCH 0/4] target/riscv/kvm: QEMU support for KVM Guest Debug on RISC-V Daniel Henrique Barboza
2024-04-09 9:43 ` Chao Du
2024-04-15 1:47 ` Chao Du
2024-04-16 9:25 ` Daniel Henrique Barboza
2024-05-20 10:22 ` Chao Du
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