Re: [PATCH qemu v6 5/6] spapr: Allow changing offset for -kernel image

[David Gibson]

On Mon, Feb 03, 2020 at 02:29:42PM +1100, Alexey Kardashevskiy wrote:
> This allows moving the kernel in the guest memory. The option is useful
> for step debugging (as Linux is linked at 0x0); it also allows loading
> grub which is normally linked to run at 0x2.
> 
> This uses the existing kernel address by default.
> 
> Signed-off-by: Alexey Kardashevskiy 

Applied to ppc-for-5.0, since I think it makes sense even without the
rest of the series.

> ---
>  include/hw/ppc/spapr.h |  1 +
>  hw/ppc/spapr.c | 38 +++---
>  2 files changed, 32 insertions(+), 7 deletions(-)
> 
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 3b50f36c338a..32e831a395ae 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -164,6 +164,7 @@ struct SpaprMachineState {
>  void *fdt_blob;
>  long kernel_size;
>  bool kernel_le;
> +uint64_t kernel_addr;
>  uint32_t initrd_base;
>  long initrd_size;
>  uint64_t rtc_offset; /* Now used only during incoming migration */
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 60153bf0b771..b59e9dc360fe 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1054,7 +1054,7 @@ static void spapr_dt_chosen(SpaprMachineState *spapr, 
> void *fdt)
>  }
>  
>  if (spapr->kernel_size) {
> -uint64_t kprop[2] = { cpu_to_be64(KERNEL_LOAD_ADDR),
> +uint64_t kprop[2] = { cpu_to_be64(spapr->kernel_addr),
>cpu_to_be64(spapr->kernel_size) };
>  
>  _FDT(fdt_setprop(fdt, chosen, "qemu,boot-kernel",
> @@ -1242,7 +1242,8 @@ void *spapr_build_fdt(SpaprMachineState *spapr, bool 
> reset, size_t space)
>  /* Build memory reserve map */
>  if (reset) {
>  if (spapr->kernel_size) {
> -_FDT((fdt_add_mem_rsv(fdt, KERNEL_LOAD_ADDR, 
> spapr->kernel_size)));
> +_FDT((fdt_add_mem_rsv(fdt, spapr->kernel_addr,
> +  spapr->kernel_size)));
>  }
>  if (spapr->initrd_size) {
>  _FDT((fdt_add_mem_rsv(fdt, spapr->initrd_base,
> @@ -1270,7 +1271,9 @@ void *spapr_build_fdt(SpaprMachineState *spapr, bool 
> reset, size_t space)
>  
>  static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
>  {
> -return (addr & 0x0fff) + KERNEL_LOAD_ADDR;
> +SpaprMachineState *spapr = opaque;
> +
> +return (addr & 0x0fff) + spapr->kernel_addr;
>  }
>  
>  static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
> @@ -2947,14 +2950,15 @@ static void spapr_machine_init(MachineState *machine)
>  uint64_t lowaddr = 0;
>  
>  spapr->kernel_size = load_elf(kernel_filename, NULL,
> -  translate_kernel_address, NULL,
> +  translate_kernel_address, spapr,
>NULL, &lowaddr, NULL, NULL, 1,
>PPC_ELF_MACHINE, 0, 0);
>  if (spapr->kernel_size == ELF_LOAD_WRONG_ENDIAN) {
>  spapr->kernel_size = load_elf(kernel_filename, NULL,
> -  translate_kernel_address, NULL, 
> NULL,
> +  translate_kernel_address, spapr, 
> NULL,
>&lowaddr, NULL, NULL, 0,
> -  PPC_ELF_MACHINE, 0, 0);
> +  PPC_ELF_MACHINE,
> +  0, 0);
>  spapr->kernel_le = spapr->kernel_size > 0;
>  }
>  if (spapr->kernel_size < 0) {
> @@ -2968,7 +2972,7 @@ static void spapr_machine_init(MachineState *machine)
>  /* Try to locate the initrd in the gap between the kernel
>   * and the firmware. Add a bit of space just in case
>   */
> -spapr->initrd_base = (KERNEL_LOAD_ADDR + spapr->kernel_size
> +spapr->initrd_base = (spapr->kernel_addr + spapr->kernel_size
>+ 0x1) & ~0x;
>  spapr->initrd_size = load_image_targphys(initrd_filename,
>   spapr->initrd_base,
> @@ -3214,6 +3218,18 @@ static void spapr_set_vsmt(Object *obj, Visitor *v, 
> const char *name,
>  visit_type_uint32(v, name, (uint32_t *)opaque, errp);
>  }
>  
> +static void spapr_get_kernel_addr(Object *obj, Visitor *v, const char *name,
> +  void *opaque, Error **errp)
> +{
> +visit_type_uint64(v, name, (uint64_t *)opaque, errp);
> +}
> +
> +static void spapr_set_kernel_addr(Object *obj, Visitor *v, const char *name,
> +  void *opaque, Error **errp)
> +{
> +visit_type_uint64(v, name, (uint64_t *)opaque, errp);
> +}
> +
>  static char *spapr_get_ic_mode(Object *obj, Error **errp)
>  {
>  SpaprMachineState *spapr = SPAPR_MACHINE(obj);
> @@ -3

Re: [PATCH qemu v6 5/6] spapr: Allow changing offset for -kernel image

[Fabiano Rosas]

Alexey Kardashevskiy  writes:

> This allows moving the kernel in the guest memory. The option is useful
> for step debugging (as Linux is linked at 0x0); it also allows loading
> grub which is normally linked to run at 0x2.
>

+1, as this fixes half of the '-S' debugging issue.

> This uses the existing kernel address by default.
>
> Signed-off-by: Alexey Kardashevskiy 

Reviewed-by: Fabiano Rosas 

> ---
>  include/hw/ppc/spapr.h |  1 +
>  hw/ppc/spapr.c | 38 +++---
>  2 files changed, 32 insertions(+), 7 deletions(-)
>
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 3b50f36c338a..32e831a395ae 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -164,6 +164,7 @@ struct SpaprMachineState {
>  void *fdt_blob;
>  long kernel_size;
>  bool kernel_le;
> +uint64_t kernel_addr;
>  uint32_t initrd_base;
>  long initrd_size;
>  uint64_t rtc_offset; /* Now used only during incoming migration */
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 60153bf0b771..b59e9dc360fe 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1054,7 +1054,7 @@ static void spapr_dt_chosen(SpaprMachineState *spapr, 
> void *fdt)
>  }
>  
>  if (spapr->kernel_size) {
> -uint64_t kprop[2] = { cpu_to_be64(KERNEL_LOAD_ADDR),
> +uint64_t kprop[2] = { cpu_to_be64(spapr->kernel_addr),
>cpu_to_be64(spapr->kernel_size) };
>  
>  _FDT(fdt_setprop(fdt, chosen, "qemu,boot-kernel",
> @@ -1242,7 +1242,8 @@ void *spapr_build_fdt(SpaprMachineState *spapr, bool 
> reset, size_t space)
>  /* Build memory reserve map */
>  if (reset) {
>  if (spapr->kernel_size) {
> -_FDT((fdt_add_mem_rsv(fdt, KERNEL_LOAD_ADDR, 
> spapr->kernel_size)));
> +_FDT((fdt_add_mem_rsv(fdt, spapr->kernel_addr,
> +  spapr->kernel_size)));
>  }
>  if (spapr->initrd_size) {
>  _FDT((fdt_add_mem_rsv(fdt, spapr->initrd_base,
> @@ -1270,7 +1271,9 @@ void *spapr_build_fdt(SpaprMachineState *spapr, bool 
> reset, size_t space)
>  
>  static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
>  {
> -return (addr & 0x0fff) + KERNEL_LOAD_ADDR;
> +SpaprMachineState *spapr = opaque;
> +
> +return (addr & 0x0fff) + spapr->kernel_addr;
>  }
>  
>  static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
> @@ -2947,14 +2950,15 @@ static void spapr_machine_init(MachineState *machine)
>  uint64_t lowaddr = 0;
>  
>  spapr->kernel_size = load_elf(kernel_filename, NULL,
> -  translate_kernel_address, NULL,
> +  translate_kernel_address, spapr,
>NULL, &lowaddr, NULL, NULL, 1,
>PPC_ELF_MACHINE, 0, 0);
>  if (spapr->kernel_size == ELF_LOAD_WRONG_ENDIAN) {
>  spapr->kernel_size = load_elf(kernel_filename, NULL,
> -  translate_kernel_address, NULL, 
> NULL,
> +  translate_kernel_address, spapr, 
> NULL,
>&lowaddr, NULL, NULL, 0,
> -  PPC_ELF_MACHINE, 0, 0);
> +  PPC_ELF_MACHINE,
> +  0, 0);
>  spapr->kernel_le = spapr->kernel_size > 0;
>  }
>  if (spapr->kernel_size < 0) {
> @@ -2968,7 +2972,7 @@ static void spapr_machine_init(MachineState *machine)
>  /* Try to locate the initrd in the gap between the kernel
>   * and the firmware. Add a bit of space just in case
>   */
> -spapr->initrd_base = (KERNEL_LOAD_ADDR + spapr->kernel_size
> +spapr->initrd_base = (spapr->kernel_addr + spapr->kernel_size
>+ 0x1) & ~0x;
>  spapr->initrd_size = load_image_targphys(initrd_filename,
>   spapr->initrd_base,
> @@ -3214,6 +3218,18 @@ static void spapr_set_vsmt(Object *obj, Visitor *v, 
> const char *name,
>  visit_type_uint32(v, name, (uint32_t *)opaque, errp);
>  }
>  
> +static void spapr_get_kernel_addr(Object *obj, Visitor *v, const char *name,
> +  void *opaque, Error **errp)
> +{
> +visit_type_uint64(v, name, (uint64_t *)opaque, errp);
> +}
> +
> +static void spapr_set_kernel_addr(Object *obj, Visitor *v, const char *name,
> +  void *opaque, Error **errp)
> +{
> +visit_type_uint64(v, name, (uint64_t *)opaque, errp);
> +}
> +
>  static char *spapr_get_ic_mode(Object *obj, Error **errp)
>  {
>  SpaprMachineState *spapr = SPAPR_MACHINE(obj);
> @@ -3319,6 +3335,14 @@ static void spapr_instance_init(

[PATCH qemu v6 5/6] spapr: Allow changing offset for -kernel image

[Alexey Kardashevskiy]

This allows moving the kernel in the guest memory. The option is useful
for step debugging (as Linux is linked at 0x0); it also allows loading
grub which is normally linked to run at 0x2.

This uses the existing kernel address by default.

Signed-off-by: Alexey Kardashevskiy 
---
 include/hw/ppc/spapr.h |  1 +
 hw/ppc/spapr.c | 38 +++---
 2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 3b50f36c338a..32e831a395ae 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -164,6 +164,7 @@ struct SpaprMachineState {
 void *fdt_blob;
 long kernel_size;
 bool kernel_le;
+uint64_t kernel_addr;
 uint32_t initrd_base;
 long initrd_size;
 uint64_t rtc_offset; /* Now used only during incoming migration */
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 60153bf0b771..b59e9dc360fe 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1054,7 +1054,7 @@ static void spapr_dt_chosen(SpaprMachineState *spapr, 
void *fdt)
 }
 
 if (spapr->kernel_size) {
-uint64_t kprop[2] = { cpu_to_be64(KERNEL_LOAD_ADDR),
+uint64_t kprop[2] = { cpu_to_be64(spapr->kernel_addr),
   cpu_to_be64(spapr->kernel_size) };
 
 _FDT(fdt_setprop(fdt, chosen, "qemu,boot-kernel",
@@ -1242,7 +1242,8 @@ void *spapr_build_fdt(SpaprMachineState *spapr, bool 
reset, size_t space)
 /* Build memory reserve map */
 if (reset) {
 if (spapr->kernel_size) {
-_FDT((fdt_add_mem_rsv(fdt, KERNEL_LOAD_ADDR, spapr->kernel_size)));
+_FDT((fdt_add_mem_rsv(fdt, spapr->kernel_addr,
+  spapr->kernel_size)));
 }
 if (spapr->initrd_size) {
 _FDT((fdt_add_mem_rsv(fdt, spapr->initrd_base,
@@ -1270,7 +1271,9 @@ void *spapr_build_fdt(SpaprMachineState *spapr, bool 
reset, size_t space)
 
 static uint64_t translate_kernel_address(void *opaque, uint64_t addr)
 {
-return (addr & 0x0fff) + KERNEL_LOAD_ADDR;
+SpaprMachineState *spapr = opaque;
+
+return (addr & 0x0fff) + spapr->kernel_addr;
 }
 
 static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
@@ -2947,14 +2950,15 @@ static void spapr_machine_init(MachineState *machine)
 uint64_t lowaddr = 0;
 
 spapr->kernel_size = load_elf(kernel_filename, NULL,
-  translate_kernel_address, NULL,
+  translate_kernel_address, spapr,
   NULL, &lowaddr, NULL, NULL, 1,
   PPC_ELF_MACHINE, 0, 0);
 if (spapr->kernel_size == ELF_LOAD_WRONG_ENDIAN) {
 spapr->kernel_size = load_elf(kernel_filename, NULL,
-  translate_kernel_address, NULL, NULL,
+  translate_kernel_address, spapr, 
NULL,
   &lowaddr, NULL, NULL, 0,
-  PPC_ELF_MACHINE, 0, 0);
+  PPC_ELF_MACHINE,
+  0, 0);
 spapr->kernel_le = spapr->kernel_size > 0;
 }
 if (spapr->kernel_size < 0) {
@@ -2968,7 +2972,7 @@ static void spapr_machine_init(MachineState *machine)
 /* Try to locate the initrd in the gap between the kernel
  * and the firmware. Add a bit of space just in case
  */
-spapr->initrd_base = (KERNEL_LOAD_ADDR + spapr->kernel_size
+spapr->initrd_base = (spapr->kernel_addr + spapr->kernel_size
   + 0x1) & ~0x;
 spapr->initrd_size = load_image_targphys(initrd_filename,
  spapr->initrd_base,
@@ -3214,6 +3218,18 @@ static void spapr_set_vsmt(Object *obj, Visitor *v, 
const char *name,
 visit_type_uint32(v, name, (uint32_t *)opaque, errp);
 }
 
+static void spapr_get_kernel_addr(Object *obj, Visitor *v, const char *name,
+  void *opaque, Error **errp)
+{
+visit_type_uint64(v, name, (uint64_t *)opaque, errp);
+}
+
+static void spapr_set_kernel_addr(Object *obj, Visitor *v, const char *name,
+  void *opaque, Error **errp)
+{
+visit_type_uint64(v, name, (uint64_t *)opaque, errp);
+}
+
 static char *spapr_get_ic_mode(Object *obj, Error **errp)
 {
 SpaprMachineState *spapr = SPAPR_MACHINE(obj);
@@ -3319,6 +3335,14 @@ static void spapr_instance_init(Object *obj)
 object_property_add_bool(obj, "vfio-no-msix-emulation",
  spapr_get_msix_emulation, NULL, NULL);
 
+object_property_add(obj, "kernel-addr", "uint64", spapr_get_kernel_addr,
+spapr_set_kernel_addr, NULL, &spapr->kernel_addr,
+&error_abort);
+