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