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Date: Mon, 4 Mar 2024 09:43:53 +0100
From: Gerd Hoffmann <kraxel@redhat.com>
To: Tao Su <tao1.su@linux.intel.com>
Cc: kvm@vger.kernel.org, Sean Christopherson <seanjc@google.com>, 
	Paolo Bonzini <pbonzini@redhat.com>, Thomas Gleixner <tglx@linutronix.de>, 
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, 
	Dave Hansen <dave.hansen@linux.intel.com>, 
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>, 
	"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/3] kvm: wire up KVM_CAP_VM_GPA_BITS for x86
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References: <20240301101410.356007-1-kraxel@redhat.com>
 <20240301101410.356007-2-kraxel@redhat.com>
 <ZeH+pPO7hhgDNujs@linux.bj.intel.com>
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> > +	kvm_caps.guest_phys_bits = boot_cpu_data.x86_phys_bits;
> 
> When KeyID_bits is non-zero, MAXPHYADDR != boot_cpu_data.x86_phys_bits
> here, you can check in detect_tme().

from detect_tme():

        /*
         * KeyID bits effectively lower the number of physical address
         * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
         */
        c->x86_phys_bits -= keyid_bits;

This looks like x86_phys_bits gets adjusted if needed.

take care,
  Gerd