* [PATCH] riscv: don't look at SUM when accessing memory from a debugger context
@ 2021-04-06 11:31 Jade Fink
2021-04-07 14:35 ` Alistair Francis
2021-04-07 14:50 ` Alistair Francis
0 siblings, 2 replies; 3+ messages in thread
From: Jade Fink @ 2021-04-06 11:31 UTC (permalink / raw)
To: qemu-devel
Cc: Jade Fink, Palmer Dabbelt, Alistair Francis, Sagar Karandikar,
Bastian Koppelmann, open list:RISC-V TCG CPUs
Previously the qemu monitor and gdbstub looked at SUM and refused to
perform accesses to user memory if it is off, which was an impediment to
debugging.
Signed-off-by: Jade Fink <qemu@jade.fyi>
---
target/riscv/cpu_helper.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 83a6bcfad0..18ea2cba57 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -299,12 +299,14 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
* @first_stage: Are we in first stage translation?
* Second stage is used for hypervisor guest translation
* @two_stage: Are we going to perform two stage translation
+ * @is_debug: Is this access from a debugger or the monitor?
*/
static int get_physical_address(CPURISCVState *env, hwaddr *physical,
int *prot, target_ulong addr,
target_ulong *fault_pte_addr,
int access_type, int mmu_idx,
- bool first_stage, bool two_stage)
+ bool first_stage, bool two_stage,
+ bool is_debug)
{
/* NOTE: the env->pc value visible here will not be
* correct, but the value visible to the exception handler
@@ -369,7 +371,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
widened = 2;
}
/* status.SUM will be ignored if execute on background */
- sum = get_field(env->mstatus, MSTATUS_SUM) || use_background;
+ sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
switch (vm) {
case VM_1_10_SV32:
levels = 2; ptidxbits = 10; ptesize = 4; break;
@@ -428,7 +430,8 @@ restart:
/* Do the second stage translation on the base PTE address. */
int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
base, NULL, MMU_DATA_LOAD,
- mmu_idx, false, true);
+ mmu_idx, false, true,
+ is_debug);
if (vbase_ret != TRANSLATE_SUCCESS) {
if (fault_pte_addr) {
@@ -616,13 +619,13 @@ hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
int mmu_idx = cpu_mmu_index(&cpu->env, false);
if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
- true, riscv_cpu_virt_enabled(env))) {
+ true, riscv_cpu_virt_enabled(env), true)) {
return -1;
}
if (riscv_cpu_virt_enabled(env)) {
if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
- 0, mmu_idx, false, true)) {
+ 0, mmu_idx, false, true, true)) {
return -1;
}
}
@@ -714,7 +717,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
/* Two stage lookup */
ret = get_physical_address(env, &pa, &prot, address,
&env->guest_phys_fault_addr, access_type,
- mmu_idx, true, true);
+ mmu_idx, true, true, false);
/*
* A G-stage exception may be triggered during two state lookup.
@@ -736,7 +739,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
im_address = pa;
ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
- access_type, mmu_idx, false, true);
+ access_type, mmu_idx, false, true,
+ false);
qemu_log_mask(CPU_LOG_MMU,
"%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
@@ -765,7 +769,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
} else {
/* Single stage lookup */
ret = get_physical_address(env, &pa, &prot, address, NULL,
- access_type, mmu_idx, true, false);
+ access_type, mmu_idx, true, false, false);
qemu_log_mask(CPU_LOG_MMU,
"%s address=%" VADDR_PRIx " ret %d physical "
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] riscv: don't look at SUM when accessing memory from a debugger context
2021-04-06 11:31 [PATCH] riscv: don't look at SUM when accessing memory from a debugger context Jade Fink
@ 2021-04-07 14:35 ` Alistair Francis
2021-04-07 14:50 ` Alistair Francis
1 sibling, 0 replies; 3+ messages in thread
From: Alistair Francis @ 2021-04-07 14:35 UTC (permalink / raw)
To: Jade Fink
Cc: open list:RISC-V TCG CPUs, Sagar Karandikar, Bastian Koppelmann,
qemu-devel@nongnu.org Developers, Alistair Francis,
Palmer Dabbelt
On Tue, Apr 6, 2021 at 9:10 AM Jade Fink <qemu@jade.fyi> wrote:
>
> Previously the qemu monitor and gdbstub looked at SUM and refused to
> perform accesses to user memory if it is off, which was an impediment to
> debugging.
>
> Signed-off-by: Jade Fink <qemu@jade.fyi>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> target/riscv/cpu_helper.c | 20 ++++++++++++--------
> 1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 83a6bcfad0..18ea2cba57 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -299,12 +299,14 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
> * @first_stage: Are we in first stage translation?
> * Second stage is used for hypervisor guest translation
> * @two_stage: Are we going to perform two stage translation
> + * @is_debug: Is this access from a debugger or the monitor?
> */
> static int get_physical_address(CPURISCVState *env, hwaddr *physical,
> int *prot, target_ulong addr,
> target_ulong *fault_pte_addr,
> int access_type, int mmu_idx,
> - bool first_stage, bool two_stage)
> + bool first_stage, bool two_stage,
> + bool is_debug)
> {
> /* NOTE: the env->pc value visible here will not be
> * correct, but the value visible to the exception handler
> @@ -369,7 +371,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
> widened = 2;
> }
> /* status.SUM will be ignored if execute on background */
> - sum = get_field(env->mstatus, MSTATUS_SUM) || use_background;
> + sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
> switch (vm) {
> case VM_1_10_SV32:
> levels = 2; ptidxbits = 10; ptesize = 4; break;
> @@ -428,7 +430,8 @@ restart:
> /* Do the second stage translation on the base PTE address. */
> int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
> base, NULL, MMU_DATA_LOAD,
> - mmu_idx, false, true);
> + mmu_idx, false, true,
> + is_debug);
>
> if (vbase_ret != TRANSLATE_SUCCESS) {
> if (fault_pte_addr) {
> @@ -616,13 +619,13 @@ hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
> int mmu_idx = cpu_mmu_index(&cpu->env, false);
>
> if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
> - true, riscv_cpu_virt_enabled(env))) {
> + true, riscv_cpu_virt_enabled(env), true)) {
> return -1;
> }
>
> if (riscv_cpu_virt_enabled(env)) {
> if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
> - 0, mmu_idx, false, true)) {
> + 0, mmu_idx, false, true, true)) {
> return -1;
> }
> }
> @@ -714,7 +717,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> /* Two stage lookup */
> ret = get_physical_address(env, &pa, &prot, address,
> &env->guest_phys_fault_addr, access_type,
> - mmu_idx, true, true);
> + mmu_idx, true, true, false);
>
> /*
> * A G-stage exception may be triggered during two state lookup.
> @@ -736,7 +739,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> im_address = pa;
>
> ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
> - access_type, mmu_idx, false, true);
> + access_type, mmu_idx, false, true,
> + false);
>
> qemu_log_mask(CPU_LOG_MMU,
> "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
> @@ -765,7 +769,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> } else {
> /* Single stage lookup */
> ret = get_physical_address(env, &pa, &prot, address, NULL,
> - access_type, mmu_idx, true, false);
> + access_type, mmu_idx, true, false, false);
>
> qemu_log_mask(CPU_LOG_MMU,
> "%s address=%" VADDR_PRIx " ret %d physical "
> --
> 2.31.1
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] riscv: don't look at SUM when accessing memory from a debugger context
2021-04-06 11:31 [PATCH] riscv: don't look at SUM when accessing memory from a debugger context Jade Fink
2021-04-07 14:35 ` Alistair Francis
@ 2021-04-07 14:50 ` Alistair Francis
1 sibling, 0 replies; 3+ messages in thread
From: Alistair Francis @ 2021-04-07 14:50 UTC (permalink / raw)
To: Jade Fink
Cc: open list:RISC-V TCG CPUs, Sagar Karandikar, Bastian Koppelmann,
qemu-devel@nongnu.org Developers, Alistair Francis,
Palmer Dabbelt
On Tue, Apr 6, 2021 at 9:10 AM Jade Fink <qemu@jade.fyi> wrote:
>
> Previously the qemu monitor and gdbstub looked at SUM and refused to
> perform accesses to user memory if it is off, which was an impediment to
> debugging.
>
> Signed-off-by: Jade Fink <qemu@jade.fyi>
Thanks!
Applied to riscv-to-apply.next
Alistair
> ---
> target/riscv/cpu_helper.c | 20 ++++++++++++--------
> 1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 83a6bcfad0..18ea2cba57 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -299,12 +299,14 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
> * @first_stage: Are we in first stage translation?
> * Second stage is used for hypervisor guest translation
> * @two_stage: Are we going to perform two stage translation
> + * @is_debug: Is this access from a debugger or the monitor?
> */
> static int get_physical_address(CPURISCVState *env, hwaddr *physical,
> int *prot, target_ulong addr,
> target_ulong *fault_pte_addr,
> int access_type, int mmu_idx,
> - bool first_stage, bool two_stage)
> + bool first_stage, bool two_stage,
> + bool is_debug)
> {
> /* NOTE: the env->pc value visible here will not be
> * correct, but the value visible to the exception handler
> @@ -369,7 +371,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
> widened = 2;
> }
> /* status.SUM will be ignored if execute on background */
> - sum = get_field(env->mstatus, MSTATUS_SUM) || use_background;
> + sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
> switch (vm) {
> case VM_1_10_SV32:
> levels = 2; ptidxbits = 10; ptesize = 4; break;
> @@ -428,7 +430,8 @@ restart:
> /* Do the second stage translation on the base PTE address. */
> int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
> base, NULL, MMU_DATA_LOAD,
> - mmu_idx, false, true);
> + mmu_idx, false, true,
> + is_debug);
>
> if (vbase_ret != TRANSLATE_SUCCESS) {
> if (fault_pte_addr) {
> @@ -616,13 +619,13 @@ hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
> int mmu_idx = cpu_mmu_index(&cpu->env, false);
>
> if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
> - true, riscv_cpu_virt_enabled(env))) {
> + true, riscv_cpu_virt_enabled(env), true)) {
> return -1;
> }
>
> if (riscv_cpu_virt_enabled(env)) {
> if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
> - 0, mmu_idx, false, true)) {
> + 0, mmu_idx, false, true, true)) {
> return -1;
> }
> }
> @@ -714,7 +717,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> /* Two stage lookup */
> ret = get_physical_address(env, &pa, &prot, address,
> &env->guest_phys_fault_addr, access_type,
> - mmu_idx, true, true);
> + mmu_idx, true, true, false);
>
> /*
> * A G-stage exception may be triggered during two state lookup.
> @@ -736,7 +739,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> im_address = pa;
>
> ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
> - access_type, mmu_idx, false, true);
> + access_type, mmu_idx, false, true,
> + false);
>
> qemu_log_mask(CPU_LOG_MMU,
> "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
> @@ -765,7 +769,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
> } else {
> /* Single stage lookup */
> ret = get_physical_address(env, &pa, &prot, address, NULL,
> - access_type, mmu_idx, true, false);
> + access_type, mmu_idx, true, false, false);
>
> qemu_log_mask(CPU_LOG_MMU,
> "%s address=%" VADDR_PRIx " ret %d physical "
> --
> 2.31.1
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-04-06 11:31 [PATCH] riscv: don't look at SUM when accessing memory from a debugger context Jade Fink
2021-04-07 14:35 ` Alistair Francis
2021-04-07 14:50 ` Alistair Francis
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