From: Zhao Liu <zhao1.liu@intel.com>
To: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>,
"Kirill Martynov" <stdcalllevi@yandex-team.ru>,
"Marcelo Tosatti" <mtosatti@redhat.com>,
"Richard Henderson" <richard.henderson@linaro.org>,
qemu-devel@nongnu.org
Subject: Re: [PATCH 1/2] i386/cpu: Enable SMM cpu addressspace
Date: Wed, 30 Jul 2025 23:20:19 +0800 [thread overview]
Message-ID: <aIo4MxukAiY0OSGE@intel.com> (raw)
In-Reply-To: <75a28dcb-88b2-4a7e-a782-a06d915e1654@intel.com>
> > > + cpu_address_space_init(cpu, 1, "cpu-smm", &smram_as_root);
> >
> > It is worth mentioning in the commit message that directly sharing
> > MemoryRegion in CPUAddressSpace is safe.
>
> It's unnecessary to me. It's common that different Address space share the
> same (root) memory region. e.g., for address space 0 for the cpu, though
> what passed in is cpu->memory, they all point to system_memory.
For cpu->memory, there's the "object_ref(OBJECT(cpu->memory))" in
cpu_exec_initfn().
But this case doesn't need to increase ref count like cpu->memory, since
memory_region_ref() provides protection and it's enough.
This is the difference.
So it sounds like now it's more necessary to clarify this, no?
next prev parent reply other threads:[~2025-07-30 16:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-29 5:40 [PATCH 0/2] i386/kvm: Enable SMM addrss space for i386 cpu Xiaoyao Li
2025-07-29 5:40 ` [PATCH 1/2] i386/cpu: Enable SMM cpu addressspace Xiaoyao Li
2025-07-29 7:08 ` Philippe Mathieu-Daudé
2025-07-30 8:11 ` Zhao Liu
2025-07-30 7:55 ` Kirill Martynov
2025-07-30 10:12 ` Xiaoyao Li
2025-07-30 15:20 ` Zhao Liu [this message]
2025-07-30 16:11 ` Xiaoyao Li
2025-07-31 3:53 ` Zhao Liu
2025-08-18 9:37 ` Kirill Martynov
2025-07-29 5:40 ` [PATCH 2/2] target/i386: Define enum X86ASIdx for x86's address spaces Xiaoyao Li
2025-07-29 7:11 ` Philippe Mathieu-Daudé
2025-07-29 12:16 ` Kirill Martynov
2025-07-30 8:23 ` Zhao Liu
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