| Message ID | 20240607115649.214622-5-salil.mehta@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add architecture agnostic code to support vCPU Hotplug | expand |
On Fri, 7 Jun 2024 12:56:45 +0100 Salil Mehta <salil.mehta@huawei.com> wrote: > OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually > results in start of the CPU scan. Scan figures out the CPU and the kind of > event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT > method with the call to \\_SB.CPUS.CSCN > > Also, macro CPU_SCAN_METHOD might be referred in other places like during GED > intialization so it makes sense to have its definition placed in some common > header file like cpu_hotplug.h. But doing this can cause compilation break > because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c one of the reasons is that you reusing legacy hw/acpi/cpu_hotplug.h, see below for suggestion. > and because both these files get compiled due to historic reasons of x86 world > i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens > during runtime [1]. To mitigate above, for now, declare a new common macro > ACPI_CPU_SCAN_METHOD for CPU scan method instead. > (This needs a separate discussion later on for clean-up) > > Reference: > [1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.com/ > > Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com> > Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> > Signed-off-by: Salil Mehta <salil.mehta@huawei.com> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Reviewed-by: Gavin Shan <gshan@redhat.com> > Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> > Tested-by: Xianglai Li <lixianglai@loongson.cn> > Tested-by: Miguel Luis <miguel.luis@oracle.com> > Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > Tested-by: Zhao Liu <zhao1.liu@intel.com> > --- > hw/acpi/cpu.c | 2 +- > hw/acpi/generic_event_device.c | 4 ++++ > include/hw/acpi/cpu_hotplug.h | 2 ++ > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c > index 473b37ba88..af2b6655d2 100644 > --- a/hw/acpi/cpu.c > +++ b/hw/acpi/cpu.c > @@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { > #define CPUHP_RES_DEVICE "PRES" > #define CPU_LOCK "CPLK" > #define CPU_STS_METHOD "CSTA" > -#define CPU_SCAN_METHOD "CSCN" > +#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD > #define CPU_NOTIFY_METHOD "CTFY" > #define CPU_EJECT_METHOD "CEJ0" > #define CPU_OST_METHOD "COST" > diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c > index 54d3b4bf9d..63226b0040 100644 > --- a/hw/acpi/generic_event_device.c > +++ b/hw/acpi/generic_event_device.c > @@ -109,6 +109,10 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, > aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "." > MEMORY_SLOT_SCAN_METHOD)); > break; > + case ACPI_GED_CPU_HOTPLUG_EVT: > + aml_append(if_ctx, aml_call0(ACPI_CPU_CONTAINER "." > + ACPI_CPU_SCAN_METHOD)); I don't particularly like exposing cpu hotplug internals for outside code and then making that code do plumbing hoping that nothing will explode in the future. build_cpus_aml() takes event_handler_method to create a method that can be called by platform. What I suggest is to call that method here instead of trying to expose CPU hotplug internals and manually building call path here. aka: build_cpus_aml(event_handler_method = PATH_TO_GED_DEVICE.CSCN) and then call here aml_append(if_ctx, aml_call0(CSCN)); which will call CSCN in GED scope, that was be populated by build_cpus_aml() to do cpu scan properly without need to expose cpu hotplug internal names and then trying to fixup conflicts caused by that. PS: we should do the same for memory hotplug, we see in context above > + break; > case ACPI_GED_PWR_DOWN_EVT: > aml_append(if_ctx, > aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE), > diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h > index 48b291e45e..ef631750b4 100644 > --- a/include/hw/acpi/cpu_hotplug.h > +++ b/include/hw/acpi/cpu_hotplug.h > @@ -20,6 +20,8 @@ > #include "hw/acpi/cpu.h" > > #define ACPI_CPU_HOTPLUG_REG_LEN 12 > +#define ACPI_CPU_SCAN_METHOD "CSCN" > +#define ACPI_CPU_CONTAINER "\\_SB.CPUS" > > typedef struct AcpiCpuHotplug { > Object *device;
Hi Igor, On 06/07/2024 14:28, Igor Mammedov wrote: > On Fri, 7 Jun 2024 12:56:45 +0100 > Salil Mehta <salil.mehta@huawei.com> wrote: > >> OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually >> results in start of the CPU scan. Scan figures out the CPU and the kind of >> event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT >> method with the call to \\_SB.CPUS.CSCN >> >> Also, macro CPU_SCAN_METHOD might be referred in other places like during GED >> intialization so it makes sense to have its definition placed in some common >> header file like cpu_hotplug.h. But doing this can cause compilation break >> because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c > one of the reasons is that you reusing legacy hw/acpi/cpu_hotplug.h, > see below for suggestion. ok > >> and because both these files get compiled due to historic reasons of x86 world >> i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens >> during runtime [1]. To mitigate above, for now, declare a new common macro >> ACPI_CPU_SCAN_METHOD for CPU scan method instead. >> (This needs a separate discussion later on for clean-up) >> >> Reference: >> [1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.com/ >> >> Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com> >> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> >> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> >> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> >> Reviewed-by: Gavin Shan <gshan@redhat.com> >> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> >> Tested-by: Xianglai Li <lixianglai@loongson.cn> >> Tested-by: Miguel Luis <miguel.luis@oracle.com> >> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> >> Tested-by: Zhao Liu <zhao1.liu@intel.com> >> --- >> hw/acpi/cpu.c | 2 +- >> hw/acpi/generic_event_device.c | 4 ++++ >> include/hw/acpi/cpu_hotplug.h | 2 ++ >> 3 files changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c >> index 473b37ba88..af2b6655d2 100644 >> --- a/hw/acpi/cpu.c >> +++ b/hw/acpi/cpu.c >> @@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { >> #define CPUHP_RES_DEVICE "PRES" >> #define CPU_LOCK "CPLK" >> #define CPU_STS_METHOD "CSTA" >> -#define CPU_SCAN_METHOD "CSCN" >> +#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD >> #define CPU_NOTIFY_METHOD "CTFY" >> #define CPU_EJECT_METHOD "CEJ0" >> #define CPU_OST_METHOD "COST" >> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c >> index 54d3b4bf9d..63226b0040 100644 >> --- a/hw/acpi/generic_event_device.c >> +++ b/hw/acpi/generic_event_device.c >> @@ -109,6 +109,10 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, >> aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "." >> MEMORY_SLOT_SCAN_METHOD)); >> break; >> + case ACPI_GED_CPU_HOTPLUG_EVT: >> + aml_append(if_ctx, aml_call0(ACPI_CPU_CONTAINER "." >> + ACPI_CPU_SCAN_METHOD)); > I don't particularly like exposing cpu hotplug internals for outside code > and then making that code do plumbing hoping that nothing will explode > in the future. I understand your point but I've followed what was already existing. For example, build_dsdt() { [...] acpi_dsdt_add_uart(scope, &memmap[VIRT_UART], (irqmap[VIRT_UART] + ARM_SPI_BASE)); if (vmc->acpi_expose_flash) { acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]); } fw_cfg_acpi_dsdt_add(scope, &memmap[VIRT_FW_CFG]); virtio_acpi_dsdt_add(scope, memmap[VIRT_MMIO].base, memmap[VIRT_MMIO].size, (irqmap[VIRT_MMIO] + ARM_SPI_BASE), 0, NUM_VIRTIO_TRANSPORTS); acpi_dsdt_add_pci(scope, memmap, irqmap[VIRT_PCIE] + ARM_SPI_BASE, vms); if (vms->acpi_dev) { build_ged_aml(scope, "\\_SB."GED_DEVICE, HOTPLUG_HANDLER(vms->acpi_dev), irqmap[VIRT_ACPI_GED] + ARM_SPI_BASE, AML_SYSTEM_MEMORY, memmap[VIRT_ACPI_GED].base); } else { acpi_dsdt_add_gpio(scope, &memmap[VIRT_GPIO], (irqmap[VIRT_GPIO] + ARM_SPI_BASE)); } [...] } Refactoring all of this code will create a noise in this patch-set. > build_cpus_aml() takes event_handler_method to create a method that > can be called by platform. What I suggest is to call that method here > instead of trying to expose CPU hotplug internals and manually building > call path here. > aka: > build_cpus_aml(event_handler_method = PATH_TO_GED_DEVICE.CSCN) > and then call here > aml_append(if_ctx, aml_call0(CSCN)); > which will call CSCN in GED scope, that was be populated by > build_cpus_aml() to do cpu scan properly without need to expose > cpu hotplug internal names and then trying to fixup conflicts caused by that. > > PS: > we should do the same for memory hotplug, we see in context above > Although. I agree with your suggested change but I think this should be carried in another patch-set. Best, Salil. > >> + break; >> case ACPI_GED_PWR_DOWN_EVT: >> aml_append(if_ctx, >> aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE), >> diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h >> index 48b291e45e..ef631750b4 100644 >> --- a/include/hw/acpi/cpu_hotplug.h >> +++ b/include/hw/acpi/cpu_hotplug.h >> @@ -20,6 +20,8 @@ >> #include "hw/acpi/cpu.h" >> >> #define ACPI_CPU_HOTPLUG_REG_LEN 12 >> +#define ACPI_CPU_SCAN_METHOD "CSCN" >> +#define ACPI_CPU_CONTAINER "\\_SB.CPUS" >> >> typedef struct AcpiCpuHotplug { >> Object *device;
On Mon, 8 Jul 2024 05:21:06 +0000 Salil Mehta <salil.mehta@opnsrc.net> wrote: > Hi Igor, > > On 06/07/2024 14:28, Igor Mammedov wrote: > > On Fri, 7 Jun 2024 12:56:45 +0100 > > Salil Mehta <salil.mehta@huawei.com> wrote: > > > >> OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually > >> results in start of the CPU scan. Scan figures out the CPU and the kind of > >> event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT > >> method with the call to \\_SB.CPUS.CSCN > >> > >> Also, macro CPU_SCAN_METHOD might be referred in other places like during GED > >> intialization so it makes sense to have its definition placed in some common > >> header file like cpu_hotplug.h. But doing this can cause compilation break > >> because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c > > one of the reasons is that you reusing legacy hw/acpi/cpu_hotplug.h, > > see below for suggestion. > ok > > > >> and because both these files get compiled due to historic reasons of x86 world > >> i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens > >> during runtime [1]. To mitigate above, for now, declare a new common macro > >> ACPI_CPU_SCAN_METHOD for CPU scan method instead. > >> (This needs a separate discussion later on for clean-up) > >> > >> Reference: > >> [1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.com/ > >> > >> Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com> > >> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> > >> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> > >> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > >> Reviewed-by: Gavin Shan <gshan@redhat.com> > >> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> > >> Tested-by: Xianglai Li <lixianglai@loongson.cn> > >> Tested-by: Miguel Luis <miguel.luis@oracle.com> > >> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > >> Tested-by: Zhao Liu <zhao1.liu@intel.com> > >> --- > >> hw/acpi/cpu.c | 2 +- > >> hw/acpi/generic_event_device.c | 4 ++++ > >> include/hw/acpi/cpu_hotplug.h | 2 ++ > >> 3 files changed, 7 insertions(+), 1 deletion(-) > >> > >> diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c > >> index 473b37ba88..af2b6655d2 100644 > >> --- a/hw/acpi/cpu.c > >> +++ b/hw/acpi/cpu.c > >> @@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { > >> #define CPUHP_RES_DEVICE "PRES" > >> #define CPU_LOCK "CPLK" > >> #define CPU_STS_METHOD "CSTA" > >> -#define CPU_SCAN_METHOD "CSCN" > >> +#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD > >> #define CPU_NOTIFY_METHOD "CTFY" > >> #define CPU_EJECT_METHOD "CEJ0" > >> #define CPU_OST_METHOD "COST" > >> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c > >> index 54d3b4bf9d..63226b0040 100644 > >> --- a/hw/acpi/generic_event_device.c > >> +++ b/hw/acpi/generic_event_device.c > >> @@ -109,6 +109,10 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, > >> aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "." > >> MEMORY_SLOT_SCAN_METHOD)); > >> break; > >> + case ACPI_GED_CPU_HOTPLUG_EVT: > >> + aml_append(if_ctx, aml_call0(ACPI_CPU_CONTAINER "." > >> + ACPI_CPU_SCAN_METHOD)); > > I don't particularly like exposing cpu hotplug internals for outside code > > and then making that code do plumbing hoping that nothing will explode > > in the future. > > I understand your point but I've followed what was already existing. > > For example, > > build_dsdt() > > { > > [...] > > acpi_dsdt_add_uart(scope, &memmap[VIRT_UART], > (irqmap[VIRT_UART] + ARM_SPI_BASE)); > if (vmc->acpi_expose_flash) { > acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]); > } > fw_cfg_acpi_dsdt_add(scope, &memmap[VIRT_FW_CFG]); > virtio_acpi_dsdt_add(scope, memmap[VIRT_MMIO].base, > memmap[VIRT_MMIO].size, > (irqmap[VIRT_MMIO] + ARM_SPI_BASE), > 0, NUM_VIRTIO_TRANSPORTS); > acpi_dsdt_add_pci(scope, memmap, irqmap[VIRT_PCIE] + ARM_SPI_BASE, > vms); > if (vms->acpi_dev) { > build_ged_aml(scope, "\\_SB."GED_DEVICE, > HOTPLUG_HANDLER(vms->acpi_dev), > irqmap[VIRT_ACPI_GED] + ARM_SPI_BASE, > AML_SYSTEM_MEMORY, > memmap[VIRT_ACPI_GED].base); > } else { > acpi_dsdt_add_gpio(scope, &memmap[VIRT_GPIO], > (irqmap[VIRT_GPIO] + ARM_SPI_BASE)); > } > > [...] > > } > > Refactoring all of this code will create a noise in this patch-set. > > build_cpus_aml() takes event_handler_method to create a method that > > can be called by platform. What I suggest is to call that method here > > instead of trying to expose CPU hotplug internals and manually building > > call path here. > > aka: > > build_cpus_aml(event_handler_method = PATH_TO_GED_DEVICE.CSCN) > > and then call here > > aml_append(if_ctx, aml_call0(CSCN)); > > which will call CSCN in GED scope, that was be populated by > > build_cpus_aml() to do cpu scan properly without need to expose > > cpu hotplug internal names and then trying to fixup conflicts caused by that. > > > > PS: > > we should do the same for memory hotplug, we see in context above > > > Although. I agree with your suggested change but I think this should be > > carried in another patch-set. I have to disagree with another patch-set on top as it introduces unnecessary code changes, wich 'another patch-set' will put back. (talking specifically about CPU hotplug) Not to mention doing as it was suggested should reduce size of your series and overall complexity. > > Best, Salil. > > > > >> + break; > >> case ACPI_GED_PWR_DOWN_EVT: > >> aml_append(if_ctx, > >> aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE), > >> diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h > >> index 48b291e45e..ef631750b4 100644 > >> --- a/include/hw/acpi/cpu_hotplug.h > >> +++ b/include/hw/acpi/cpu_hotplug.h > >> @@ -20,6 +20,8 @@ > >> #include "hw/acpi/cpu.h" > >> > >> #define ACPI_CPU_HOTPLUG_REG_LEN 12 > >> +#define ACPI_CPU_SCAN_METHOD "CSCN" > >> +#define ACPI_CPU_CONTAINER "\\_SB.CPUS" > >> > >> typedef struct AcpiCpuHotplug { > >> Object *device; >
Hi Igor, On 06/07/2024 14:28, Igor Mammedov wrote: > On Fri, 7 Jun 2024 12:56:45 +0100 > Salil Mehta <salil.mehta@huawei.com> wrote: > >> OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually >> results in start of the CPU scan. Scan figures out the CPU and the kind of >> event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT >> method with the call to \\_SB.CPUS.CSCN >> >> Also, macro CPU_SCAN_METHOD might be referred in other places like during GED >> intialization so it makes sense to have its definition placed in some common >> header file like cpu_hotplug.h. But doing this can cause compilation break >> because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c > one of the reasons is that you reusing legacy hw/acpi/cpu_hotplug.h, > see below for suggestion. > >> and because both these files get compiled due to historic reasons of x86 world >> i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens >> during runtime [1]. To mitigate above, for now, declare a new common macro >> ACPI_CPU_SCAN_METHOD for CPU scan method instead. >> (This needs a separate discussion later on for clean-up) >> >> Reference: >> [1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.com/ >> >> Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com> >> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> >> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> >> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> >> Reviewed-by: Gavin Shan <gshan@redhat.com> >> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> >> Tested-by: Xianglai Li <lixianglai@loongson.cn> >> Tested-by: Miguel Luis <miguel.luis@oracle.com> >> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> >> Tested-by: Zhao Liu <zhao1.liu@intel.com> >> --- >> hw/acpi/cpu.c | 2 +- >> hw/acpi/generic_event_device.c | 4 ++++ >> include/hw/acpi/cpu_hotplug.h | 2 ++ >> 3 files changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c >> index 473b37ba88..af2b6655d2 100644 >> --- a/hw/acpi/cpu.c >> +++ b/hw/acpi/cpu.c >> @@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { >> #define CPUHP_RES_DEVICE "PRES" >> #define CPU_LOCK "CPLK" >> #define CPU_STS_METHOD "CSTA" >> -#define CPU_SCAN_METHOD "CSCN" >> +#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD >> #define CPU_NOTIFY_METHOD "CTFY" >> #define CPU_EJECT_METHOD "CEJ0" >> #define CPU_OST_METHOD "COST" >> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c >> index 54d3b4bf9d..63226b0040 100644 >> --- a/hw/acpi/generic_event_device.c >> +++ b/hw/acpi/generic_event_device.c >> @@ -109,6 +109,10 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, >> aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "." >> MEMORY_SLOT_SCAN_METHOD)); >> break; >> + case ACPI_GED_CPU_HOTPLUG_EVT: >> + aml_append(if_ctx, aml_call0(ACPI_CPU_CONTAINER "." >> + ACPI_CPU_SCAN_METHOD)); > I don't particularly like exposing cpu hotplug internals for outside code > and then making that code do plumbing hoping that nothing will explode > in the future. > > build_cpus_aml() takes event_handler_method to create a method that > can be called by platform. What I suggest is to call that method here > instead of trying to expose CPU hotplug internals and manually building > call path here. > aka: > build_cpus_aml(event_handler_method = PATH_TO_GED_DEVICE.CSCN) > and then call here > aml_append(if_ctx, aml_call0(CSCN)); > which will call CSCN in GED scope, that was be populated by > build_cpus_aml() to do cpu scan properly without need to expose > cpu hotplug internal names and then trying to fixup conflicts caused by that. > > PS: > we should do the same for memory hotplug, we see in context above In the x86 world and ARM, two different types of event handling mechanisms are used: one based on GPE and the other on GED. The latter has its own placeholder within the generic_event_device.c file, which also multiplexes other GED events. Multiplexing AMLs for two different types of handlers into build_cpus_aml() seems to be a fundamental mistake here. For CPU handling, this should also not be done because x86 deals with legacy hotplug and modern hotplug differently but still uses the same GPE-based event handling for both. Moreover, which type of handler should be used depends upon the context from which build_cpus_aml() is called and it would be ugly to demultiplex these inside the build_cpus_aml() code. Therefore, my suggestion is: 1. Keep the CPU’s _EVT handling code in the generic_event_device.c as it is. 2. Pull out the event handler method and CPU scan call-related initialization entirely out of the CPU’s AML code (i.e., both in build_cpus_aml() and build_legacy_cpu_hotplug_aml()). 3. Remove the input parameter of event_handler in build_cpus_aml(). 4. Create a separate function like build_gpe_aml() and use this function in the following places: File: hw/i386/acpi-build.c build_dsdt() { [...] scope = aml_scope("_GPE"); [...] aml_append(dsdt, scope); if (pcmc->legacy_cpu_hotplug) { build_legacy_cpu_hotplug_aml(dsdt, machine, pm->cpu_hp_io_base); } else { CPUHotplugFeatures opts = { .acpi_1_compatible = true, .has_legacy_cphp = true, .smi_path = pm->smi_on_cpuhp ? "\\_SB.PCI0.SMI0.SMIC" : NULL, .fw_unplugs_cpu = pm->smi_on_cpu_unplug, }; build_cpus_aml(dsdt, machine, opts, pc_madt_cpu_entry, - pm->cpu_hp_io_base, "\\_SB.PCI0", "\\_GPE._E02"); + pm->cpu_hp_io_base, "\\_SB.PCI0"); + build_gpe_aml(...,, ,"\\_GPE._E02") } [...] } File: hw/acpi/cpu.c @@ -343,9 +343,10 @@ const VMStateDescription vmstate_cpu_hotplug = { #define CPU_FW_EJECT_EVENT "CEJF" void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts, - build_madt_cpu_fn build_madt_cpu, hwaddr io_base, + build_madt_cpu_fn build_madt_cpu, hwaddr base_addr, const char *res_root, - const char *event_handler_method) + AmlRegionSpace rs) { Aml *ifctx; Aml *field; That said, if you still wish you proceed with your suggestions I can go ahead and do it but please understand that I'll have to put a check to avoid adding call to CPU Scan for am/virt platform since we would want to add that call as part of the GED/AML code. This is unnecessary and would look ugly. Thanks Salil. > > >> + break; >> case ACPI_GED_PWR_DOWN_EVT: >> aml_append(if_ctx, >> aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE), >> diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h >> index 48b291e45e..ef631750b4 100644 >> --- a/include/hw/acpi/cpu_hotplug.h >> +++ b/include/hw/acpi/cpu_hotplug.h >> @@ -20,6 +20,8 @@ >> #include "hw/acpi/cpu.h" >> >> #define ACPI_CPU_HOTPLUG_REG_LEN 12 >> +#define ACPI_CPU_SCAN_METHOD "CSCN" >> +#define ACPI_CPU_CONTAINER "\\_SB.CPUS" >> >> typedef struct AcpiCpuHotplug { >> Object *device;
On Thu, 11 Jul 2024 03:29:40 +0000 Salil Mehta <salil.mehta@opnsrc.net> wrote: > Hi Igor, > > > On 06/07/2024 14:28, Igor Mammedov wrote: > > On Fri, 7 Jun 2024 12:56:45 +0100 > > Salil Mehta <salil.mehta@huawei.com> wrote: > > > >> OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually > >> results in start of the CPU scan. Scan figures out the CPU and the kind of > >> event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT > >> method with the call to \\_SB.CPUS.CSCN > >> > >> Also, macro CPU_SCAN_METHOD might be referred in other places like during GED > >> intialization so it makes sense to have its definition placed in some common > >> header file like cpu_hotplug.h. But doing this can cause compilation break > >> because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c > > one of the reasons is that you reusing legacy hw/acpi/cpu_hotplug.h, > > see below for suggestion. > > > >> and because both these files get compiled due to historic reasons of x86 world > >> i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens > >> during runtime [1]. To mitigate above, for now, declare a new common macro > >> ACPI_CPU_SCAN_METHOD for CPU scan method instead. > >> (This needs a separate discussion later on for clean-up) > >> > >> Reference: > >> [1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.com/ > >> > >> Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com> > >> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> > >> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> > >> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > >> Reviewed-by: Gavin Shan <gshan@redhat.com> > >> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> > >> Tested-by: Xianglai Li <lixianglai@loongson.cn> > >> Tested-by: Miguel Luis <miguel.luis@oracle.com> > >> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > >> Tested-by: Zhao Liu <zhao1.liu@intel.com> > >> --- > >> hw/acpi/cpu.c | 2 +- > >> hw/acpi/generic_event_device.c | 4 ++++ > >> include/hw/acpi/cpu_hotplug.h | 2 ++ > >> 3 files changed, 7 insertions(+), 1 deletion(-) > >> > >> diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c > >> index 473b37ba88..af2b6655d2 100644 > >> --- a/hw/acpi/cpu.c > >> +++ b/hw/acpi/cpu.c > >> @@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { > >> #define CPUHP_RES_DEVICE "PRES" > >> #define CPU_LOCK "CPLK" > >> #define CPU_STS_METHOD "CSTA" > >> -#define CPU_SCAN_METHOD "CSCN" > >> +#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD > >> #define CPU_NOTIFY_METHOD "CTFY" > >> #define CPU_EJECT_METHOD "CEJ0" > >> #define CPU_OST_METHOD "COST" > >> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c > >> index 54d3b4bf9d..63226b0040 100644 > >> --- a/hw/acpi/generic_event_device.c > >> +++ b/hw/acpi/generic_event_device.c > >> @@ -109,6 +109,10 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, > >> aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "." > >> MEMORY_SLOT_SCAN_METHOD)); > >> break; > >> + case ACPI_GED_CPU_HOTPLUG_EVT: > >> + aml_append(if_ctx, aml_call0(ACPI_CPU_CONTAINER "." > >> + ACPI_CPU_SCAN_METHOD)); > > I don't particularly like exposing cpu hotplug internals for outside code > > and then making that code do plumbing hoping that nothing will explode > > in the future. > > > > build_cpus_aml() takes event_handler_method to create a method that > > can be called by platform. What I suggest is to call that method here > > instead of trying to expose CPU hotplug internals and manually building > > call path here. > > aka: > > build_cpus_aml(event_handler_method = PATH_TO_GED_DEVICE.CSCN) > > and then call here > > aml_append(if_ctx, aml_call0(CSCN)); > > which will call CSCN in GED scope, that was be populated by > > build_cpus_aml() to do cpu scan properly without need to expose > > cpu hotplug internal names and then trying to fixup conflicts caused by that. > > > > PS: > > we should do the same for memory hotplug, we see in context above > > In the x86 world and ARM, two different types of event handling > mechanisms are > used: one based on GPE and the other on GED. The latter has its own > placeholder > within the generic_event_device.c file, which also multiplexes other GED > events. > Multiplexing AMLs for two different types of handlers into > build_cpus_aml() seems > to be a fundamental mistake here. For CPU handling, this should also not > be done > because x86 deals with legacy hotplug and modern hotplug differently but > still > uses the same GPE-based event handling for both. Moreover, which type of > handler > should be used depends upon the context from which build_cpus_aml() is > called > and it would be ugly to demultiplex these inside the build_cpus_aml() code. > > Therefore, my suggestion is: > 1. Keep the CPU’s _EVT handling code in the generic_event_device.c as it is. > 2. Pull out the event handler method and CPU scan call-related > initialization entirely > out of the CPU’s AML code (i.e., both in build_cpus_aml() and > build_legacy_cpu_hotplug_aml()). > 3. Remove the input parameter of event_handler in build_cpus_aml(). > 4. Create a separate function like build_gpe_aml() and use this function > in the > following places: > > File: hw/i386/acpi-build.c I'm not convinced by above arguments yet (perhaps I don't see a problem you are observing), so I'd like to keep cpu hotplug isolated/not exposed as much as possible unless it's proven that it will not work as is. (see for more below) > build_dsdt() > { > [...] > scope = aml_scope("_GPE"); > [...] > aml_append(dsdt, scope); > > if (pcmc->legacy_cpu_hotplug) { > build_legacy_cpu_hotplug_aml(dsdt, machine, pm->cpu_hp_io_base); > } else { > CPUHotplugFeatures opts = { > .acpi_1_compatible = true, .has_legacy_cphp = true, > .smi_path = pm->smi_on_cpuhp ? "\\_SB.PCI0.SMI0.SMIC" : NULL, > .fw_unplugs_cpu = pm->smi_on_cpu_unplug, > }; > build_cpus_aml(dsdt, machine, opts, pc_madt_cpu_entry, > - pm->cpu_hp_io_base, "\\_SB.PCI0", "\\_GPE._E02"); > + pm->cpu_hp_io_base, "\\_SB.PCI0"); > + build_gpe_aml(...,, ,"\\_GPE._E02") > > } > [...] > } > > File: hw/acpi/cpu.c > > @@ -343,9 +343,10 @@ const VMStateDescription vmstate_cpu_hotplug = { > #define CPU_FW_EJECT_EVENT "CEJF" > > void build_cpus_aml(Aml *table, MachineState *machine, > CPUHotplugFeatures opts, > - build_madt_cpu_fn build_madt_cpu, hwaddr io_base, > + build_madt_cpu_fn build_madt_cpu, hwaddr base_addr, > const char *res_root, > - const char *event_handler_method) > + AmlRegionSpace rs) > { > Aml *ifctx; > Aml *field; > > > That said, if you still wish you proceed with your suggestions I can go > ahead and do it but please understand that I'll have to put a check > to avoid adding call to CPU Scan for am/virt platform since we would > want to add that call as part of the GED/AML code. This is unnecessary > and would look ugly. I just don't get why you have to call CPU Scan explicitly from arm/virt side. (maybe my suggestion was lost in translation/was not clear enough) Let's pretend that hw/i386/acpi-build.c is an arm/virt code and demo what I was suggesting. diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c index 2d6e91b124..33addb6275 100644 --- a/hw/acpi/generic_event_device.c +++ b/hw/acpi/generic_event_device.c @@ -117,6 +117,9 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, aml_notify(aml_name("\\_SB.NVDR"), aml_int(0x80))); break; + case ACPI_GED_CPU_HOTPLUG_EVT: + aml_append(if_ctx, aml_call0("\\_SB.GED.CPEV")); + break default: /* * Please make sure all the events in ged_supported_events[] diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index f4e366f64f..8b4f422652 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -1536,7 +1536,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, .fw_unplugs_cpu = pm->smi_on_cpu_unplug, }; build_cpus_aml(dsdt, machine, opts, pc_madt_cpu_entry, - pm->cpu_hp_io_base, "\\_SB.PCI0", "\\_GPE._E02"); + pm->cpu_hp_io_base, "\\_SB.PCI0", "\\_SB.GED.CPEV"); } this way build_cpus_aml() will create and populate with scan \\_SB.GED.CPEV method. which is then called by GED._EVT() ... if cpuhotplug \\_SB.GED.CPEV() ... there is no multiplexing of cpuhp event in build_cpus_aml, the only event multiplexer is GED._EVT() as it should be. And you don't have to expose cpu hotplug internals to any other place[s]. PS: For legacy cphp handling acpi/cpu.c has only _INI method that is created when opts.has_legacy_cphp is true. we should be able to get rid of it when 2.6 machine type is removed. But ARM [or anything else] don't have to be aware of it if you use static initializer like it's done in hw/i386/acpi-build.c and just ignore non relevant fields. > Thanks > Salil. > > > > > > > >> + break; > >> case ACPI_GED_PWR_DOWN_EVT: > >> aml_append(if_ctx, > >> aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE), > >> diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h > >> index 48b291e45e..ef631750b4 100644 > >> --- a/include/hw/acpi/cpu_hotplug.h > >> +++ b/include/hw/acpi/cpu_hotplug.h > >> @@ -20,6 +20,8 @@ > >> #include "hw/acpi/cpu.h" > >> > >> #define ACPI_CPU_HOTPLUG_REG_LEN 12 > >> +#define ACPI_CPU_SCAN_METHOD "CSCN" > >> +#define ACPI_CPU_CONTAINER "\\_SB.CPUS" > >> > >> typedef struct AcpiCpuHotplug { > >> Object *device; >
On 11/07/2024 08:34, Igor Mammedov wrote: > On Thu, 11 Jul 2024 03:29:40 +0000 > Salil Mehta <salil.mehta@opnsrc.net> wrote: > >> Hi Igor, >> >> >> On 06/07/2024 14:28, Igor Mammedov wrote: >>> On Fri, 7 Jun 2024 12:56:45 +0100 >>> Salil Mehta <salil.mehta@huawei.com> wrote: >>> >>>> OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually >>>> results in start of the CPU scan. Scan figures out the CPU and the kind of >>>> event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT >>>> method with the call to \\_SB.CPUS.CSCN >>>> >>>> Also, macro CPU_SCAN_METHOD might be referred in other places like during GED >>>> intialization so it makes sense to have its definition placed in some common >>>> header file like cpu_hotplug.h. But doing this can cause compilation break >>>> because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c >>> one of the reasons is that you reusing legacy hw/acpi/cpu_hotplug.h, >>> see below for suggestion. >>> >>>> and because both these files get compiled due to historic reasons of x86 world >>>> i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens >>>> during runtime [1]. To mitigate above, for now, declare a new common macro >>>> ACPI_CPU_SCAN_METHOD for CPU scan method instead. >>>> (This needs a separate discussion later on for clean-up) >>>> >>>> Reference: >>>> [1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.com/ >>>> >>>> Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com> >>>> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> >>>> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> >>>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> >>>> Reviewed-by: Gavin Shan <gshan@redhat.com> >>>> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> >>>> Tested-by: Xianglai Li <lixianglai@loongson.cn> >>>> Tested-by: Miguel Luis <miguel.luis@oracle.com> >>>> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> >>>> Tested-by: Zhao Liu <zhao1.liu@intel.com> [...] > diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c > index 2d6e91b124..33addb6275 100644 > --- a/hw/acpi/generic_event_device.c > +++ b/hw/acpi/generic_event_device.c > @@ -117,6 +117,9 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, > aml_notify(aml_name("\\_SB.NVDR"), > aml_int(0x80))); > break; > + case ACPI_GED_CPU_HOTPLUG_EVT: > + aml_append(if_ctx, aml_call0("\\_SB.GED.CPEV")); > + break > default: > /* > * Please make sure all the events in ged_supported_events[] > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > index f4e366f64f..8b4f422652 100644 > --- a/hw/i386/acpi-build.c > +++ b/hw/i386/acpi-build.c > @@ -1536,7 +1536,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, > .fw_unplugs_cpu = pm->smi_on_cpu_unplug, > }; > build_cpus_aml(dsdt, machine, opts, pc_madt_cpu_entry, > - pm->cpu_hp_io_base, "\\_SB.PCI0", "\\_GPE._E02"); > + pm->cpu_hp_io_base, "\\_SB.PCI0", "\\_SB.GED.CPEV"); > } > > this way build_cpus_aml() will create and populate with scan > \\_SB.GED.CPEV method. I see. Perhaps, I failed to realise the semantics in the AML sense i.e. exporting a call to a method belonging to one scope to another (\\_SB.CPUS to \\_SB.GED). Yes, with above change we can avoid calling \\_SB.CPUS.CSCN method direclty from within GED _EVT. Sorry for the noise. I will do the change. Thanks > PS: > For legacy cphp handling acpi/cpu.c has only _INI method > that is created when opts.has_legacy_cphp is true. > we should be able to get rid of it when 2.6 machine type is removed. > But ARM [or anything else] don't have to be aware of it > if you use static initializer like it's done in hw/i386/acpi-build.c > and just ignore non relevant fields. ok. thanks for the clarification. Best regards Salil.
diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c index 473b37ba88..af2b6655d2 100644 --- a/hw/acpi/cpu.c +++ b/hw/acpi/cpu.c @@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = { #define CPUHP_RES_DEVICE "PRES" #define CPU_LOCK "CPLK" #define CPU_STS_METHOD "CSTA" -#define CPU_SCAN_METHOD "CSCN" +#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD #define CPU_NOTIFY_METHOD "CTFY" #define CPU_EJECT_METHOD "CEJ0" #define CPU_OST_METHOD "COST" diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c index 54d3b4bf9d..63226b0040 100644 --- a/hw/acpi/generic_event_device.c +++ b/hw/acpi/generic_event_device.c @@ -109,6 +109,10 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev, aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "." MEMORY_SLOT_SCAN_METHOD)); break; + case ACPI_GED_CPU_HOTPLUG_EVT: + aml_append(if_ctx, aml_call0(ACPI_CPU_CONTAINER "." + ACPI_CPU_SCAN_METHOD)); + break; case ACPI_GED_PWR_DOWN_EVT: aml_append(if_ctx, aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE), diff --git a/include/hw/acpi/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h index 48b291e45e..ef631750b4 100644 --- a/include/hw/acpi/cpu_hotplug.h +++ b/include/hw/acpi/cpu_hotplug.h @@ -20,6 +20,8 @@ #include "hw/acpi/cpu.h" #define ACPI_CPU_HOTPLUG_REG_LEN 12 +#define ACPI_CPU_SCAN_METHOD "CSCN" +#define ACPI_CPU_CONTAINER "\\_SB.CPUS" typedef struct AcpiCpuHotplug { Object *device;