pc: fail memory hot-plug/unplug with -no-acpi and Q35 machine type

[Qemu-devel] [PATCH] pc: fail memory hot-plug/unplug with -no-acpi and Q35 machine type

Posted by Haozhong Zhang 6 years, 4 months ago

When -no-acpi option is used with Q35 machine type, no guest ACPI is
built, but the ACPI device is still created, so only checking the
presence of ACPI device before memory plug/unplug is not enough in
such cases. Check whether ACPI is disabled globally in addition and
fail memory plug/unplug if it's disabled.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
 hw/i386/pc.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 3fcf318a95..55686bf5d8 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1695,9 +1695,14 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         align = memory_region_get_alignment(mr);
     }
 
-    if (!pcms->acpi_dev) {
+    /*
+     * When -no-acpi is used with Q35 machine type, no ACPI is built,
+     * but pcms->acpi_dev is still created. Check !acpi_enabled in
+     * addition to cover this case.
+     */
+    if (!pcms->acpi_dev || !acpi_enabled) {
         error_setg(&local_err,
-                   "memory hotplug is not enabled: missing acpi device");
+                   "memory hotplug is not enabled: missing acpi device or acpi disabled");
         goto out;
     }
 
@@ -1729,9 +1734,14 @@ static void pc_dimm_unplug_request(HotplugHandler *hotplug_dev,
     Error *local_err = NULL;
     PCMachineState *pcms = PC_MACHINE(hotplug_dev);
 
-    if (!pcms->acpi_dev) {
+    /*
+     * When -no-acpi is used with Q35 machine type, no ACPI is built,
+     * but pcms->acpi_dev is still created. Check !acpi_enabled in
+     * addition to cover this case.
+     */
+    if (!pcms->acpi_dev || !acpi_enabled) {
         error_setg(&local_err,
-                   "memory hotplug is not enabled: missing acpi device");
+                   "memory hotplug is not enabled: missing acpi device or acpi disabled");
         goto out;
     }
 
-- 
2.14.1

Re: [Qemu-devel] [PATCH] pc: fail memory hot-plug/unplug with -no-acpi and Q35 machine type

Posted by Igor Mammedov 6 years, 4 months ago

On Fri, 22 Dec 2017 09:51:20 +0800
Haozhong Zhang <haozhong.zhang@intel.com> wrote:

> When -no-acpi option is used with Q35 machine type, no guest ACPI is
> built, but the ACPI device is still created, so only checking the
> presence of ACPI device before memory plug/unplug is not enough in
> such cases. Check whether ACPI is disabled globally in addition and
> fail memory plug/unplug if it's disabled.
> 
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
we do not expose dimms in E820, so there is no point in allowing them
being added (hot or cold-plug) without acpi enabled as guest
won't be able to know where they are located.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  hw/i386/pc.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 3fcf318a95..55686bf5d8 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1695,9 +1695,14 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
>          align = memory_region_get_alignment(mr);
>      }
>  
> -    if (!pcms->acpi_dev) {
> +    /*
> +     * When -no-acpi is used with Q35 machine type, no ACPI is built,
> +     * but pcms->acpi_dev is still created. Check !acpi_enabled in
> +     * addition to cover this case.
> +     */
> +    if (!pcms->acpi_dev || !acpi_enabled) {
>          error_setg(&local_err,
> -                   "memory hotplug is not enabled: missing acpi device");
> +                   "memory hotplug is not enabled: missing acpi device or acpi disabled");
>          goto out;
>      }
>  
> @@ -1729,9 +1734,14 @@ static void pc_dimm_unplug_request(HotplugHandler *hotplug_dev,
>      Error *local_err = NULL;
>      PCMachineState *pcms = PC_MACHINE(hotplug_dev);
>  
> -    if (!pcms->acpi_dev) {
> +    /*
> +     * When -no-acpi is used with Q35 machine type, no ACPI is built,
> +     * but pcms->acpi_dev is still created. Check !acpi_enabled in
> +     * addition to cover this case.
> +     */
> +    if (!pcms->acpi_dev || !acpi_enabled) {
>          error_setg(&local_err,
> -                   "memory hotplug is not enabled: missing acpi device");
> +                   "memory hotplug is not enabled: missing acpi device or acpi disabled");
>          goto out;
>      }
>

Re: [Qemu-devel] [PATCH] pc: fail memory hot-plug/unplug with -no-acpi and Q35 machine type

Posted by Paolo Bonzini 6 years, 4 months ago

On 22/12/2017 02:51, Haozhong Zhang wrote:
> When -no-acpi option is used with Q35 machine type, no guest ACPI is
> built, but the ACPI device is still created, so only checking the
> presence of ACPI device before memory plug/unplug is not enough in
> such cases. Check whether ACPI is disabled globally in addition and
> fail memory plug/unplug if it's disabled.
> 
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
> ---
>  hw/i386/pc.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 3fcf318a95..55686bf5d8 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1695,9 +1695,14 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
>          align = memory_region_get_alignment(mr);
>      }
>  
> -    if (!pcms->acpi_dev) {
> +    /*
> +     * When -no-acpi is used with Q35 machine type, no ACPI is built,
> +     * but pcms->acpi_dev is still created. Check !acpi_enabled in
> +     * addition to cover this case.
> +     */
> +    if (!pcms->acpi_dev || !acpi_enabled) {
>          error_setg(&local_err,
> -                   "memory hotplug is not enabled: missing acpi device");
> +                   "memory hotplug is not enabled: missing acpi device or acpi disabled");
>          goto out;
>      }
>  
> @@ -1729,9 +1734,14 @@ static void pc_dimm_unplug_request(HotplugHandler *hotplug_dev,
>      Error *local_err = NULL;
>      PCMachineState *pcms = PC_MACHINE(hotplug_dev);
>  
> -    if (!pcms->acpi_dev) {
> +    /*
> +     * When -no-acpi is used with Q35 machine type, no ACPI is built,
> +     * but pcms->acpi_dev is still created. Check !acpi_enabled in
> +     * addition to cover this case.
> +     */
> +    if (!pcms->acpi_dev || !acpi_enabled) {
>          error_setg(&local_err,
> -                   "memory hotplug is not enabled: missing acpi device");
> +                   "memory hotplug is not enabled: missing acpi device or acpi disabled");
>          goto out;
>      }
>  
> 

Queued, thanks.

Paolo