Re: [Qemu-devel] [RFC QEMU PATCH v4 05/10] xen-hvm: initialize fw_cfg interface

[Haozhong Zhang]

On 02/27/18 16:46 +, Anthony PERARD wrote:
> On Thu, Dec 07, 2017 at 06:18:07PM +0800, Haozhong Zhang wrote:
> > Xen is going to reuse QEMU to build ACPI of some devices (e.g., NFIT
> > and SSDT for NVDIMM) for HVM domains. The existing QEMU ACPI build
> > code requires a fw_cfg interface which will also be used to pass QEMU
> > built ACPI to Xen. Therefore, we need to initialize fw_cfg when any
> > ACPI is going to be built by QEMU.
> > 
> > Signed-off-by: Haozhong Zhang 
> > ---
> > Cc: Stefano Stabellini 
> > Cc: Anthony Perard 
> > Cc: "Michael S. Tsirkin" 
> > Cc: Paolo Bonzini 
> > Cc: Richard Henderson 
> > Cc: Eduardo Habkost 
> > ---
> >  hw/i386/xen/xen-hvm.c | 12 
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
> > index fe01b7a025..4b29f4052b 100644
> > --- a/hw/i386/xen/xen-hvm.c
> > +++ b/hw/i386/xen/xen-hvm.c
> > @@ -14,6 +14,7 @@
> >  #include "hw/pci/pci.h"
> >  #include "hw/i386/pc.h"
> >  #include "hw/i386/apic-msidef.h"
> > +#include "hw/loader.h"
> >  #include "hw/xen/xen_common.h"
> >  #include "hw/xen/xen_backend.h"
> >  #include "qmp-commands.h"
> > @@ -1234,6 +1235,14 @@ static void xen_wakeup_notifier(Notifier *notifier, 
> > void *data)
> >  xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
> >  }
> >  
> > +static void xen_fw_cfg_init(PCMachineState *pcms)
> > +{
> 
> The fw_cfg interface might already be initialized, it is used for
> "direct kernel boot" on hvm. It is initialized in xen_load_linux().
>

xen_hvm_init() --> xen_fw_cfg_init() are called before
xen_load_linux(). I'll add a check in xen_load_linux() to avoid
redoing fw_cfg_init_io and rom_set_fw.

Haozhong

> > +FWCfgState *fw_cfg = fw_cfg_init_io(FW_CFG_IO_BASE);
> > +
> > +rom_set_fw(fw_cfg);
> > +pcms->fw_cfg = fw_cfg;
> > +}
> > +
> >  void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
> >  {
> >  int i, rc;
> > @@ -1384,6 +1393,9 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion 
> > **ram_memory)
> >  
> >  /* Disable ACPI build because Xen handles it */
> >  pcms->acpi_build_enabled = false;
> > +if (pcms->acpi_build_enabled) {
> > +xen_fw_cfg_init(pcms);
> > +}
> >  
> >  return;
> >  
> > -- 
> > 2.15.1
> > 
> 
> -- 
> Anthony PERARD

Re: [Qemu-devel] [RFC QEMU PATCH v4 05/10] xen-hvm: initialize fw_cfg interface

[Anthony PERARD]

On Thu, Dec 07, 2017 at 06:18:07PM +0800, Haozhong Zhang wrote:
> Xen is going to reuse QEMU to build ACPI of some devices (e.g., NFIT
> and SSDT for NVDIMM) for HVM domains. The existing QEMU ACPI build
> code requires a fw_cfg interface which will also be used to pass QEMU
> built ACPI to Xen. Therefore, we need to initialize fw_cfg when any
> ACPI is going to be built by QEMU.
> 
> Signed-off-by: Haozhong Zhang 
> ---
> Cc: Stefano Stabellini 
> Cc: Anthony Perard 
> Cc: "Michael S. Tsirkin" 
> Cc: Paolo Bonzini 
> Cc: Richard Henderson 
> Cc: Eduardo Habkost 
> ---
>  hw/i386/xen/xen-hvm.c | 12 
>  1 file changed, 12 insertions(+)
> 
> diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
> index fe01b7a025..4b29f4052b 100644
> --- a/hw/i386/xen/xen-hvm.c
> +++ b/hw/i386/xen/xen-hvm.c
> @@ -14,6 +14,7 @@
>  #include "hw/pci/pci.h"
>  #include "hw/i386/pc.h"
>  #include "hw/i386/apic-msidef.h"
> +#include "hw/loader.h"
>  #include "hw/xen/xen_common.h"
>  #include "hw/xen/xen_backend.h"
>  #include "qmp-commands.h"
> @@ -1234,6 +1235,14 @@ static void xen_wakeup_notifier(Notifier *notifier, 
> void *data)
>  xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
>  }
>  
> +static void xen_fw_cfg_init(PCMachineState *pcms)
> +{

The fw_cfg interface might already be initialized, it is used for
"direct kernel boot" on hvm. It is initialized in xen_load_linux().

> +FWCfgState *fw_cfg = fw_cfg_init_io(FW_CFG_IO_BASE);
> +
> +rom_set_fw(fw_cfg);
> +pcms->fw_cfg = fw_cfg;
> +}
> +
>  void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
>  {
>  int i, rc;
> @@ -1384,6 +1393,9 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion 
> **ram_memory)
>  
>  /* Disable ACPI build because Xen handles it */
>  pcms->acpi_build_enabled = false;
> +if (pcms->acpi_build_enabled) {
> +xen_fw_cfg_init(pcms);
> +}
>  
>  return;
>  
> -- 
> 2.15.1
> 

-- 
Anthony PERARD

[Qemu-devel] [RFC QEMU PATCH v4 05/10] xen-hvm: initialize fw_cfg interface

[Haozhong Zhang]

Xen is going to reuse QEMU to build ACPI of some devices (e.g., NFIT
and SSDT for NVDIMM) for HVM domains. The existing QEMU ACPI build
code requires a fw_cfg interface which will also be used to pass QEMU
built ACPI to Xen. Therefore, we need to initialize fw_cfg when any
ACPI is going to be built by QEMU.

Signed-off-by: Haozhong Zhang 
---
Cc: Stefano Stabellini 
Cc: Anthony Perard 
Cc: "Michael S. Tsirkin" 
Cc: Paolo Bonzini 
Cc: Richard Henderson 
Cc: Eduardo Habkost 
---
 hw/i386/xen/xen-hvm.c | 12 
 1 file changed, 12 insertions(+)

diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
index fe01b7a025..4b29f4052b 100644
--- a/hw/i386/xen/xen-hvm.c
+++ b/hw/i386/xen/xen-hvm.c
@@ -14,6 +14,7 @@
 #include "hw/pci/pci.h"
 #include "hw/i386/pc.h"
 #include "hw/i386/apic-msidef.h"
+#include "hw/loader.h"
 #include "hw/xen/xen_common.h"
 #include "hw/xen/xen_backend.h"
 #include "qmp-commands.h"
@@ -1234,6 +1235,14 @@ static void xen_wakeup_notifier(Notifier *notifier, void 
*data)
 xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
 }
 
+static void xen_fw_cfg_init(PCMachineState *pcms)
+{
+FWCfgState *fw_cfg = fw_cfg_init_io(FW_CFG_IO_BASE);
+
+rom_set_fw(fw_cfg);
+pcms->fw_cfg = fw_cfg;
+}
+
 void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory)
 {
 int i, rc;
@@ -1384,6 +1393,9 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion 
**ram_memory)
 
 /* Disable ACPI build because Xen handles it */
 pcms->acpi_build_enabled = false;
+if (pcms->acpi_build_enabled) {
+xen_fw_cfg_init(pcms);
+}
 
 return;
 
-- 
2.15.1