[PATCH v2 0/2] riscv: fix --enable-debug in riscv-to-apply.next

[PATCH v2 0/2] riscv: fix --enable-debug in riscv-to-apply.next

[Daniel Henrique Barboza]

Hi,

This is the second version of the --enable-debug build fix for the
riscv-to-apply.next branch:

https://github.com/alistair23/qemu/tree/riscv-to-apply.next

This implements suggestions from Richard Henderson made in v1. Most
notable difference is that riscv_kvm_aplic_request() was moved to
kvm.c and it's now being declared in kvm_riscv.h.

Changes from v1:
- changed patch order
- patch 1 (former 2):
  - use kvm_enabled() to crop the whole block
- patch 2 (former 1):
  - move riscv_kvm_aplic_request() to kvm_riscv.h
  - use kvm_enabled() to crop the whole block
- v1 link: https://lore.kernel.org/qemu-riscv/20230829122144.464489-1-dbarboza@ventanamicro.com/


Daniel Henrique Barboza (2):
  hw/riscv/virt.c: fix non-KVM --enable-debug build
  hw/intc/riscv_aplic.c fix non-KVM --enable-debug build

 hw/intc/riscv_aplic.c    | 8 ++------
 hw/riscv/virt.c          | 6 +++---
 target/riscv/kvm.c       | 5 +++++
 target/riscv/kvm_riscv.h | 1 +
 4 files changed, 11 insertions(+), 9 deletions(-)

-- 
2.41.0

[PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Daniel Henrique Barboza]

A build with --enable-debug and without KVM will fail as follows:

/usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'

This happens because the code block with "if virt_use_kvm_aia(s)" isn't
being ignored by the debug build, resulting in an undefined reference to
a KVM only function.

Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
make the compiler crop the kvm_riscv_aia_create() call entirely from a
non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
virt_use_kvm_aia() won't fix the build because this function would need
to be inlined multiple times to make the compiler zero out the entire
block.

While we're at it, use kvm_enabled() in all instances where
virt_use_kvm_aia() is checked to allow the compiler to elide these other
kvm-only instances as well.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 hw/riscv/virt.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index 388e52a294..3b259b9305 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -782,7 +782,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
     }
 
     /* KVM AIA only has one APLIC instance */
-    if (virt_use_kvm_aia(s)) {
+    if (kvm_enabled() && virt_use_kvm_aia(s)) {
         create_fdt_socket_aplic(s, memmap, 0,
                                 msi_m_phandle, msi_s_phandle, phandle,
                                 &intc_phandles[0], xplic_phandles,
@@ -808,7 +808,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
 
     g_free(intc_phandles);
 
-    if (virt_use_kvm_aia(s)) {
+    if (kvm_enabled() && virt_use_kvm_aia(s)) {
         *irq_mmio_phandle = xplic_phandles[0];
         *irq_virtio_phandle = xplic_phandles[0];
         *irq_pcie_phandle = xplic_phandles[0];
@@ -1461,7 +1461,7 @@ static void virt_machine_init(MachineState *machine)
         }
     }
 
-    if (virt_use_kvm_aia(s)) {
+    if (kvm_enabled() && virt_use_kvm_aia(s)) {
         kvm_riscv_aia_create(machine, IMSIC_MMIO_GROUP_MIN_SHIFT,
                              VIRT_IRQCHIP_NUM_SOURCES, VIRT_IRQCHIP_NUM_MSIS,
                              memmap[VIRT_APLIC_S].base,
-- 
2.41.0

Re: [PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Richard Henderson]

On 8/30/23 06:35, Daniel Henrique Barboza wrote:
> A build with --enable-debug and without KVM will fail as follows:
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
> ./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'
> 
> This happens because the code block with "if virt_use_kvm_aia(s)" isn't
> being ignored by the debug build, resulting in an undefined reference to
> a KVM only function.
> 
> Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
> make the compiler crop the kvm_riscv_aia_create() call entirely from a
> non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
> virt_use_kvm_aia() won't fix the build because this function would need
> to be inlined multiple times to make the compiler zero out the entire
> block.
> 
> While we're at it, use kvm_enabled() in all instances where
> virt_use_kvm_aia() is checked to allow the compiler to elide these other
> kvm-only instances as well.
> 
> Suggested-by: Richard Henderson<richard.henderson@linaro.org>
> Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
> Signed-off-by: Daniel Henrique Barboza<dbarboza@ventanamicro.com>
> ---
>   hw/riscv/virt.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Re: [PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Philippe Mathieu-Daudé]

On 30/8/23 15:35, Daniel Henrique Barboza wrote:
> A build with --enable-debug and without KVM will fail as follows:
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
> ./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'
> 
> This happens because the code block with "if virt_use_kvm_aia(s)" isn't
> being ignored by the debug build, resulting in an undefined reference to
> a KVM only function.
> 
> Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
> make the compiler crop the kvm_riscv_aia_create() call entirely from a
> non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
> virt_use_kvm_aia() won't fix the build because this function would need
> to be inlined multiple times to make the compiler zero out the entire
> block.
> 
> While we're at it, use kvm_enabled() in all instances where
> virt_use_kvm_aia() is checked to allow the compiler to elide these other
> kvm-only instances as well.
> 
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   hw/riscv/virt.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)

Yay!

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Andrew Jones]

On Wed, Aug 30, 2023 at 10:35:02AM -0300, Daniel Henrique Barboza wrote:
> A build with --enable-debug and without KVM will fail as follows:
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
> ./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'
> 
> This happens because the code block with "if virt_use_kvm_aia(s)" isn't
> being ignored by the debug build, resulting in an undefined reference to
> a KVM only function.
> 
> Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
> make the compiler crop the kvm_riscv_aia_create() call entirely from a
> non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
> virt_use_kvm_aia() won't fix the build because this function would need
> to be inlined multiple times to make the compiler zero out the entire
> block.
> 
> While we're at it, use kvm_enabled() in all instances where
> virt_use_kvm_aia() is checked to allow the compiler to elide these other
> kvm-only instances as well.
> 
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  hw/riscv/virt.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 388e52a294..3b259b9305 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -782,7 +782,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
>      }
>  
>      /* KVM AIA only has one APLIC instance */
> -    if (virt_use_kvm_aia(s)) {
> +    if (kvm_enabled() && virt_use_kvm_aia(s)) {
>          create_fdt_socket_aplic(s, memmap, 0,
>                                  msi_m_phandle, msi_s_phandle, phandle,
>                                  &intc_phandles[0], xplic_phandles,
> @@ -808,7 +808,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
>  
>      g_free(intc_phandles);
>  
> -    if (virt_use_kvm_aia(s)) {
> +    if (kvm_enabled() && virt_use_kvm_aia(s)) {
>          *irq_mmio_phandle = xplic_phandles[0];
>          *irq_virtio_phandle = xplic_phandles[0];
>          *irq_pcie_phandle = xplic_phandles[0];
> @@ -1461,7 +1461,7 @@ static void virt_machine_init(MachineState *machine)
>          }
>      }
>  
> -    if (virt_use_kvm_aia(s)) {
> +    if (kvm_enabled() && virt_use_kvm_aia(s)) {
>          kvm_riscv_aia_create(machine, IMSIC_MMIO_GROUP_MIN_SHIFT,
>                               VIRT_IRQCHIP_NUM_SOURCES, VIRT_IRQCHIP_NUM_MSIS,
>                               memmap[VIRT_APLIC_S].base,
> -- 
> 2.41.0
> 
>

I think I'd prefer

 /* We need this inlined for debug (-O0) builds */
 static inline QEMU_ALWAYS_INLINE bool virt_use_kvm_aia(RISCVVirtState *s)
 {
    return kvm_enabled() && kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
 }

assuming that works.

Either way,

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew

Re: [PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Daniel Henrique Barboza]

On 8/31/23 05:42, Andrew Jones wrote:
> On Wed, Aug 30, 2023 at 10:35:02AM -0300, Daniel Henrique Barboza wrote:
>> A build with --enable-debug and without KVM will fail as follows:
>>
>> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
>> ./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'
>>
>> This happens because the code block with "if virt_use_kvm_aia(s)" isn't
>> being ignored by the debug build, resulting in an undefined reference to
>> a KVM only function.
>>
>> Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
>> make the compiler crop the kvm_riscv_aia_create() call entirely from a
>> non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
>> virt_use_kvm_aia() won't fix the build because this function would need
>> to be inlined multiple times to make the compiler zero out the entire
>> block.
>>
>> While we're at it, use kvm_enabled() in all instances where
>> virt_use_kvm_aia() is checked to allow the compiler to elide these other
>> kvm-only instances as well.
>>
>> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
>> Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   hw/riscv/virt.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
>> index 388e52a294..3b259b9305 100644
>> --- a/hw/riscv/virt.c
>> +++ b/hw/riscv/virt.c
>> @@ -782,7 +782,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
>>       }
>>   
>>       /* KVM AIA only has one APLIC instance */
>> -    if (virt_use_kvm_aia(s)) {
>> +    if (kvm_enabled() && virt_use_kvm_aia(s)) {
>>           create_fdt_socket_aplic(s, memmap, 0,
>>                                   msi_m_phandle, msi_s_phandle, phandle,
>>                                   &intc_phandles[0], xplic_phandles,
>> @@ -808,7 +808,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
>>   
>>       g_free(intc_phandles);
>>   
>> -    if (virt_use_kvm_aia(s)) {
>> +    if (kvm_enabled() && virt_use_kvm_aia(s)) {
>>           *irq_mmio_phandle = xplic_phandles[0];
>>           *irq_virtio_phandle = xplic_phandles[0];
>>           *irq_pcie_phandle = xplic_phandles[0];
>> @@ -1461,7 +1461,7 @@ static void virt_machine_init(MachineState *machine)
>>           }
>>       }
>>   
>> -    if (virt_use_kvm_aia(s)) {
>> +    if (kvm_enabled() && virt_use_kvm_aia(s)) {
>>           kvm_riscv_aia_create(machine, IMSIC_MMIO_GROUP_MIN_SHIFT,
>>                                VIRT_IRQCHIP_NUM_SOURCES, VIRT_IRQCHIP_NUM_MSIS,
>>                                memmap[VIRT_APLIC_S].base,
>> -- 
>> 2.41.0
>>
>>
> 
> I think I'd prefer
> 
>   /* We need this inlined for debug (-O0) builds */
>   static inline QEMU_ALWAYS_INLINE bool virt_use_kvm_aia(RISCVVirtState *s)
>   {
>      return kvm_enabled() && kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
>   }
> 
> assuming that works.


I've tried before with 'inline' but not with 'QEMU_ALWAYS_INLINE'. But unfortunately
it doesn't work too:


diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index 3b259b9305..a600d81e77 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -77,9 +77,10 @@
  #endif
  
  /* KVM AIA only supports APLIC MSI. APLIC Wired is always emulated by QEMU. */
-static bool virt_use_kvm_aia(RISCVVirtState *s)
+static inline QEMU_ALWAYS_INLINE bool virt_use_kvm_aia(RISCVVirtState *s)
  {
-    return kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
+    return kvm_enabled() && kvm_irqchip_in_kernel() &&
+           s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
  }
  
  static const MemMapEntry virt_memmap[] = {
@@ -782,7 +783,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
      }
  
      /* KVM AIA only has one APLIC instance */
-    if (kvm_enabled() && virt_use_kvm_aia(s)) {
+    if (virt_use_kvm_aia(s)) {
          create_fdt_socket_aplic(s, memmap, 0,
                                  msi_m_phandle, msi_s_phandle, phandle,
                                  &intc_phandles[0], xplic_phandles,
@@ -808,7 +809,7 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
  
      g_free(intc_phandles);
  
-    if (kvm_enabled() && virt_use_kvm_aia(s)) {
+    if (virt_use_kvm_aia(s)) {
          *irq_mmio_phandle = xplic_phandles[0];
          *irq_virtio_phandle = xplic_phandles[0];
          *irq_pcie_phandle = xplic_phandles[0];
@@ -1461,7 +1462,7 @@ static void virt_machine_init(MachineState *machine)
          }
      }
  
-    if (kvm_enabled() && virt_use_kvm_aia(s)) {
+    if (virt_use_kvm_aia(s)) {
          kvm_riscv_aia_create(machine, IMSIC_MMIO_GROUP_MIN_SHIFT,
                               VIRT_IRQCHIP_NUM_SOURCES, VIRT_IRQCHIP_NUM_MSIS,
                               memmap[VIRT_APLIC_S].base,


Same error:

/libssh.so -lrbd -lrados -lbz2 -lutil -Wl,--end-group
/usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
/home/danielhb/work/qemu/build/../hw/riscv/virt.c:1466: undefined reference to `kvm_riscv_aia_create'
collect2: error: ld returned 1 exit status



Thanks,


Daniel




> 
> Either way,
> 
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> 
> Thanks,
> drew

Re: [PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Philippe Mathieu-Daudé]

On 31/8/23 10:42, Andrew Jones wrote:
> On Wed, Aug 30, 2023 at 10:35:02AM -0300, Daniel Henrique Barboza wrote:
>> A build with --enable-debug and without KVM will fail as follows:
>>
>> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
>> ./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'
>>
>> This happens because the code block with "if virt_use_kvm_aia(s)" isn't
>> being ignored by the debug build, resulting in an undefined reference to
>> a KVM only function.
>>
>> Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
>> make the compiler crop the kvm_riscv_aia_create() call entirely from a
>> non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
>> virt_use_kvm_aia() won't fix the build because this function would need
>> to be inlined multiple times to make the compiler zero out the entire
>> block.
>>
>> While we're at it, use kvm_enabled() in all instances where
>> virt_use_kvm_aia() is checked to allow the compiler to elide these other
>> kvm-only instances as well.
>>
>> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
>> Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   hw/riscv/virt.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)


> I think I'd prefer
> 
>   /* We need this inlined for debug (-O0) builds */
>   static inline QEMU_ALWAYS_INLINE bool virt_use_kvm_aia(RISCVVirtState *s)
>   {
>      return kvm_enabled() && kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;

Generally we should know whether KVM is enabled or not _before_
calling any foo_kvm() code, not after.

>   }

Re: [PATCH v2 1/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Andrew Jones]

On Thu, Aug 31, 2023 at 02:47:54PM +0200, Philippe Mathieu-Daudé wrote:
> On 31/8/23 10:42, Andrew Jones wrote:
> > On Wed, Aug 30, 2023 at 10:35:02AM -0300, Daniel Henrique Barboza wrote:
> > > A build with --enable-debug and without KVM will fail as follows:
> > > 
> > > /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
> > > ./qemu/build/../hw/riscv/virt.c:1465: undefined reference to `kvm_riscv_aia_create'
> > > 
> > > This happens because the code block with "if virt_use_kvm_aia(s)" isn't
> > > being ignored by the debug build, resulting in an undefined reference to
> > > a KVM only function.
> > > 
> > > Add a 'kvm_enabled()' conditional together with virt_use_kvm_aia() will
> > > make the compiler crop the kvm_riscv_aia_create() call entirely from a
> > > non-KVM build. Note that adding the 'kvm_enabled()' conditional inside
> > > virt_use_kvm_aia() won't fix the build because this function would need
> > > to be inlined multiple times to make the compiler zero out the entire
> > > block.
> > > 
> > > While we're at it, use kvm_enabled() in all instances where
> > > virt_use_kvm_aia() is checked to allow the compiler to elide these other
> > > kvm-only instances as well.
> > > 
> > > Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> > > Fixes: dbdb99948e ("target/riscv: select KVM AIA in riscv virt machine")
> > > Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> > > ---
> > >   hw/riscv/virt.c | 6 +++---
> > >   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> 
> > I think I'd prefer
> > 
> >   /* We need this inlined for debug (-O0) builds */
> >   static inline QEMU_ALWAYS_INLINE bool virt_use_kvm_aia(RISCVVirtState *s)
> >   {
> >      return kvm_enabled() && kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
> 
> Generally we should know whether KVM is enabled or not _before_
> calling any foo_kvm() code, not after.

That's reasonable and makes me want to suggest squashing the diff below
into the second patch.


diff --git a/hw/intc/riscv_aplic.c b/hw/intc/riscv_aplic.c
index 592c3ce76828..f712699a4040 100644
--- a/hw/intc/riscv_aplic.c
+++ b/hw/intc/riscv_aplic.c
@@ -816,7 +816,7 @@ static void riscv_aplic_realize(DeviceState *dev, Error **errp)
     uint32_t i;
     RISCVAPLICState *aplic = RISCV_APLIC(dev);
 
-    if (!is_kvm_aia(aplic->msimode)) {
+    if (!kvm_enabled() || !is_kvm_aia(aplic->msimode)) {
         aplic->bitfield_words = (aplic->num_irqs + 31) >> 5;
         aplic->sourcecfg = g_new0(uint32_t, aplic->num_irqs);
         aplic->state = g_new0(uint32_t, aplic->num_irqs);
@@ -980,7 +980,7 @@ DeviceState *riscv_aplic_create(hwaddr addr, hwaddr size,
 
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
 
-    if (!is_kvm_aia(msimode)) {
+    if (!kvm_enabled() || !is_kvm_aia(msimode)) {
         sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
     }

[PATCH v2 2/2] hw/intc/riscv_aplic.c fix non-KVM --enable-debug build

[Daniel Henrique Barboza]

Commit 6df0b37e2ab breaks a --enable-debug build in a non-KVM
environment with the following error:

/usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_intc_riscv_aplic.c.o: in function `riscv_kvm_aplic_request':
./qemu/build/../hw/intc/riscv_aplic.c:486: undefined reference to `kvm_set_irq'
collect2: error: ld returned 1 exit status

This happens because the debug build will poke into the
'if (is_kvm_aia(aplic->msimode))' block and fail to find a reference to
the KVM only function riscv_kvm_aplic_request().

There are multiple solutions to fix this. We'll go with the same
solution from the previous patch, i.e. add a kvm_enabled() conditional
to filter out the block. But there's a catch: riscv_kvm_aplic_request()
is a local function that would end up being used if the compiler crops
the block, and this won't work. Quoting Richard Henderson's explanation
in [1]:

"(...) the compiler won't eliminate entire unused functions with -O0"

We'll solve it by moving riscv_kvm_aplic_request() to kvm.c and add its
declaration in kvm_riscv.h, where all other KVM specific public
functions are already declared. Other archs handles KVM specific code in
this manner and we expect to do the same from now on.

[1] https://lore.kernel.org/qemu-riscv/d2f1ad02-eb03-138f-9d08-db676deeed05@linaro.org/

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 hw/intc/riscv_aplic.c    | 8 ++------
 target/riscv/kvm.c       | 5 +++++
 target/riscv/kvm_riscv.h | 1 +
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/hw/intc/riscv_aplic.c b/hw/intc/riscv_aplic.c
index 592c3ce768..99aae8ccbe 100644
--- a/hw/intc/riscv_aplic.c
+++ b/hw/intc/riscv_aplic.c
@@ -32,6 +32,7 @@
 #include "target/riscv/cpu.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
+#include "kvm_riscv.h"
 #include "migration/vmstate.h"
 
 #define APLIC_MAX_IDC                  (1UL << 14)
@@ -481,11 +482,6 @@ static uint32_t riscv_aplic_idc_claimi(RISCVAPLICState *aplic, uint32_t idc)
     return topi;
 }
 
-static void riscv_kvm_aplic_request(void *opaque, int irq, int level)
-{
-    kvm_set_irq(kvm_state, irq, !!level);
-}
-
 static void riscv_aplic_request(void *opaque, int irq, int level)
 {
     bool update = false;
@@ -840,7 +836,7 @@ static void riscv_aplic_realize(DeviceState *dev, Error **errp)
      * have IRQ lines delegated by their parent APLIC.
      */
     if (!aplic->parent) {
-        if (is_kvm_aia(aplic->msimode)) {
+        if (kvm_enabled() && is_kvm_aia(aplic->msimode)) {
             qdev_init_gpio_in(dev, riscv_kvm_aplic_request, aplic->num_irqs);
         } else {
             qdev_init_gpio_in(dev, riscv_aplic_request, aplic->num_irqs);
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index faee8536ef..ac28a70723 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -46,6 +46,11 @@
 #include "sysemu/runstate.h"
 #include "hw/riscv/numa.h"
 
+void riscv_kvm_aplic_request(void *opaque, int irq, int level)
+{
+    kvm_set_irq(kvm_state, irq, !!level);
+}
+
 static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
                                  uint64_t idx)
 {
diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
index 7d4b7c60e2..de8c209ebc 100644
--- a/target/riscv/kvm_riscv.h
+++ b/target/riscv/kvm_riscv.h
@@ -26,5 +26,6 @@ void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
                           uint64_t aia_irq_num, uint64_t aia_msi_num,
                           uint64_t aplic_base, uint64_t imsic_base,
                           uint64_t guest_num);
+void riscv_kvm_aplic_request(void *opaque, int irq, int level);
 
 #endif
-- 
2.41.0

Re: [PATCH v2 2/2] hw/intc/riscv_aplic.c fix non-KVM --enable-debug build

[Richard Henderson]

On 8/30/23 06:35, Daniel Henrique Barboza wrote:
> Commit 6df0b37e2ab breaks a --enable-debug build in a non-KVM
> environment with the following error:
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_intc_riscv_aplic.c.o: in function `riscv_kvm_aplic_request':
> ./qemu/build/../hw/intc/riscv_aplic.c:486: undefined reference to `kvm_set_irq'
> collect2: error: ld returned 1 exit status
> 
> This happens because the debug build will poke into the
> 'if (is_kvm_aia(aplic->msimode))' block and fail to find a reference to
> the KVM only function riscv_kvm_aplic_request().
> 
> There are multiple solutions to fix this. We'll go with the same
> solution from the previous patch, i.e. add a kvm_enabled() conditional
> to filter out the block. But there's a catch: riscv_kvm_aplic_request()
> is a local function that would end up being used if the compiler crops
> the block, and this won't work. Quoting Richard Henderson's explanation
> in [1]:
> 
> "(...) the compiler won't eliminate entire unused functions with -O0"
> 
> We'll solve it by moving riscv_kvm_aplic_request() to kvm.c and add its
> declaration in kvm_riscv.h, where all other KVM specific public
> functions are already declared. Other archs handles KVM specific code in
> this manner and we expect to do the same from now on.
> 
> [1] https://lore.kernel.org/qemu-riscv/d2f1ad02-eb03-138f-9d08-db676deeed05@linaro.org/
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   hw/intc/riscv_aplic.c    | 8 ++------
>   target/riscv/kvm.c       | 5 +++++
>   target/riscv/kvm_riscv.h | 1 +
>   3 files changed, 8 insertions(+), 6 deletions(-)

Much better.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

Re: [PATCH v2 2/2] hw/intc/riscv_aplic.c fix non-KVM --enable-debug build

[Philippe Mathieu-Daudé]

On 30/8/23 15:35, Daniel Henrique Barboza wrote:
> Commit 6df0b37e2ab breaks a --enable-debug build in a non-KVM
> environment with the following error:
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_intc_riscv_aplic.c.o: in function `riscv_kvm_aplic_request':
> ./qemu/build/../hw/intc/riscv_aplic.c:486: undefined reference to `kvm_set_irq'
> collect2: error: ld returned 1 exit status
> 
> This happens because the debug build will poke into the
> 'if (is_kvm_aia(aplic->msimode))' block and fail to find a reference to
> the KVM only function riscv_kvm_aplic_request().
> 
> There are multiple solutions to fix this. We'll go with the same
> solution from the previous patch, i.e. add a kvm_enabled() conditional
> to filter out the block. But there's a catch: riscv_kvm_aplic_request()
> is a local function that would end up being used if the compiler crops
> the block, and this won't work. Quoting Richard Henderson's explanation
> in [1]:
> 
> "(...) the compiler won't eliminate entire unused functions with -O0"
> 
> We'll solve it by moving riscv_kvm_aplic_request() to kvm.c and add its
> declaration in kvm_riscv.h, where all other KVM specific public
> functions are already declared. Other archs handles KVM specific code in
> this manner and we expect to do the same from now on.
> 
> [1] https://lore.kernel.org/qemu-riscv/d2f1ad02-eb03-138f-9d08-db676deeed05@linaro.org/
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   hw/intc/riscv_aplic.c    | 8 ++------
>   target/riscv/kvm.c       | 5 +++++
>   target/riscv/kvm_riscv.h | 1 +
>   3 files changed, 8 insertions(+), 6 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v2 2/2] hw/intc/riscv_aplic.c fix non-KVM --enable-debug build

[Andrew Jones]

On Wed, Aug 30, 2023 at 10:35:03AM -0300, Daniel Henrique Barboza wrote:
> Commit 6df0b37e2ab breaks a --enable-debug build in a non-KVM
> environment with the following error:
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_intc_riscv_aplic.c.o: in function `riscv_kvm_aplic_request':
> ./qemu/build/../hw/intc/riscv_aplic.c:486: undefined reference to `kvm_set_irq'
> collect2: error: ld returned 1 exit status
> 
> This happens because the debug build will poke into the
> 'if (is_kvm_aia(aplic->msimode))' block and fail to find a reference to
> the KVM only function riscv_kvm_aplic_request().
> 
> There are multiple solutions to fix this. We'll go with the same
> solution from the previous patch, i.e. add a kvm_enabled() conditional
> to filter out the block. But there's a catch: riscv_kvm_aplic_request()
> is a local function that would end up being used if the compiler crops
> the block, and this won't work. Quoting Richard Henderson's explanation
> in [1]:
> 
> "(...) the compiler won't eliminate entire unused functions with -O0"
> 
> We'll solve it by moving riscv_kvm_aplic_request() to kvm.c and add its
> declaration in kvm_riscv.h, where all other KVM specific public
> functions are already declared. Other archs handles KVM specific code in
> this manner and we expect to do the same from now on.
> 
> [1] https://lore.kernel.org/qemu-riscv/d2f1ad02-eb03-138f-9d08-db676deeed05@linaro.org/
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  hw/intc/riscv_aplic.c    | 8 ++------
>  target/riscv/kvm.c       | 5 +++++
>  target/riscv/kvm_riscv.h | 1 +
>  3 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/intc/riscv_aplic.c b/hw/intc/riscv_aplic.c
> index 592c3ce768..99aae8ccbe 100644
> --- a/hw/intc/riscv_aplic.c
> +++ b/hw/intc/riscv_aplic.c
> @@ -32,6 +32,7 @@
>  #include "target/riscv/cpu.h"
>  #include "sysemu/sysemu.h"
>  #include "sysemu/kvm.h"
> +#include "kvm_riscv.h"
>  #include "migration/vmstate.h"
>  
>  #define APLIC_MAX_IDC                  (1UL << 14)
> @@ -481,11 +482,6 @@ static uint32_t riscv_aplic_idc_claimi(RISCVAPLICState *aplic, uint32_t idc)
>      return topi;
>  }
>  
> -static void riscv_kvm_aplic_request(void *opaque, int irq, int level)
> -{
> -    kvm_set_irq(kvm_state, irq, !!level);
> -}
> -
>  static void riscv_aplic_request(void *opaque, int irq, int level)
>  {
>      bool update = false;
> @@ -840,7 +836,7 @@ static void riscv_aplic_realize(DeviceState *dev, Error **errp)
>       * have IRQ lines delegated by their parent APLIC.
>       */
>      if (!aplic->parent) {
> -        if (is_kvm_aia(aplic->msimode)) {
> +        if (kvm_enabled() && is_kvm_aia(aplic->msimode)) {
>              qdev_init_gpio_in(dev, riscv_kvm_aplic_request, aplic->num_irqs);
>          } else {
>              qdev_init_gpio_in(dev, riscv_aplic_request, aplic->num_irqs);
> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> index faee8536ef..ac28a70723 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -46,6 +46,11 @@
>  #include "sysemu/runstate.h"
>  #include "hw/riscv/numa.h"
>  
> +void riscv_kvm_aplic_request(void *opaque, int irq, int level)
> +{
> +    kvm_set_irq(kvm_state, irq, !!level);
> +}
> +
>  static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
>                                   uint64_t idx)
>  {
> diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
> index 7d4b7c60e2..de8c209ebc 100644
> --- a/target/riscv/kvm_riscv.h
> +++ b/target/riscv/kvm_riscv.h
> @@ -26,5 +26,6 @@ void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
>                            uint64_t aia_irq_num, uint64_t aia_msi_num,
>                            uint64_t aplic_base, uint64_t imsic_base,
>                            uint64_t guest_num);
> +void riscv_kvm_aplic_request(void *opaque, int irq, int level);
>  
>  #endif
> -- 
> 2.41.0
> 
>

I'd also try the always_inline trick with is_kvm_aia(), particularly
because now we're inconsistent with how it's used. In two of the three
places it's called we don't guard it with kvm_enabled().

But, I'm also mostly OK with this, so

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew

Re: [PATCH v2 0/2] riscv: fix --enable-debug in riscv-to-apply.next

[Alistair Francis]

On Wed, Aug 30, 2023 at 11:36 PM Daniel Henrique Barboza
<dbarboza@ventanamicro.com> wrote:
>
> Hi,
>
> This is the second version of the --enable-debug build fix for the
> riscv-to-apply.next branch:
>
> https://github.com/alistair23/qemu/tree/riscv-to-apply.next
>
> This implements suggestions from Richard Henderson made in v1. Most
> notable difference is that riscv_kvm_aplic_request() was moved to
> kvm.c and it's now being declared in kvm_riscv.h.

Thanks!

Applied to riscv-to-apply.next

Alistair

>
> Changes from v1:
> - changed patch order
> - patch 1 (former 2):
>   - use kvm_enabled() to crop the whole block
> - patch 2 (former 1):
>   - move riscv_kvm_aplic_request() to kvm_riscv.h
>   - use kvm_enabled() to crop the whole block
> - v1 link: https://lore.kernel.org/qemu-riscv/20230829122144.464489-1-dbarboza@ventanamicro.com/
>
>
> Daniel Henrique Barboza (2):
>   hw/riscv/virt.c: fix non-KVM --enable-debug build
>   hw/intc/riscv_aplic.c fix non-KVM --enable-debug build
>
>  hw/intc/riscv_aplic.c    | 8 ++------
>  hw/riscv/virt.c          | 6 +++---
>  target/riscv/kvm.c       | 5 +++++
>  target/riscv/kvm_riscv.h | 1 +
>  4 files changed, 11 insertions(+), 9 deletions(-)
>
> --
> 2.41.0
>
>