From: Sean Christopherson <seanjc@google.com>
To: Binbin Wu <binbin.wu@linux.intel.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
pbonzini@redhat.com, chao.gao@intel.com, kai.huang@intel.com,
David.Laight@aculab.com, robert.hu@linux.intel.com,
guang.zeng@intel.com
Subject: Re: [PATCH v10 7/9] KVM: VMX: Implement and wire get_untagged_addr() for LAM
Date: Wed, 16 Aug 2023 15:01:51 -0700 [thread overview]
Message-ID: <ZN1HT61WM0Pmxqmr@google.com> (raw)
In-Reply-To: <20230719144131.29052-8-binbin.wu@linux.intel.com>
On Wed, Jul 19, 2023, Binbin Wu wrote:
> + return (sign_extend64(gva, lam_bit) & ~BIT_ULL(63)) | (gva & BIT_ULL(63));
Almost forgot. Please add a comment explaning how LAM untags the address,
specifically the whole bit 63 preservation. The logic is actually straightforward,
but the above looks way more complex than it actually is. This?
/*
* Untag the address by sign-extending the LAM bit, but NOT to bit 63.
* Bit 63 is retained from the raw virtual address so that untagging
* doesn't change a user access to a supervisor access, and vice versa.
*/
next prev parent reply other threads:[~2023-08-16 22:02 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-19 14:41 [PATCH v10 0/9] Linear Address Masking (LAM) KVM Enabling Binbin Wu
2023-07-19 14:41 ` [PATCH v10 1/9] KVM: x86/mmu: Use GENMASK_ULL() to define __PT_BASE_ADDR_MASK Binbin Wu
2023-08-16 21:00 ` Sean Christopherson
2023-08-28 4:06 ` Binbin Wu
2023-08-31 19:26 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 2/9] KVM: x86: Add & use kvm_vcpu_is_legal_cr3() to check CR3's legality Binbin Wu
2023-07-20 23:53 ` Isaku Yamahata
2023-07-21 2:20 ` Binbin Wu
2023-07-21 15:03 ` Sean Christopherson
2023-07-24 2:07 ` Binbin Wu
2023-07-25 16:05 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 3/9] KVM: x86: Use KVM-governed feature framework to track "LAM enabled" Binbin Wu
2023-08-16 3:46 ` Huang, Kai
2023-08-16 7:08 ` Binbin Wu
2023-08-16 9:47 ` Huang, Kai
2023-08-16 21:33 ` Sean Christopherson
2023-08-16 23:03 ` Huang, Kai
2023-08-17 1:28 ` Binbin Wu
2023-08-17 19:46 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 4/9] KVM: x86: Virtualize CR4.LAM_SUP Binbin Wu
2023-08-16 21:41 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 5/9] KVM: x86: Virtualize CR3.LAM_{U48,U57} Binbin Wu
2023-08-16 21:44 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 6/9] KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in emulator Binbin Wu
2023-07-19 14:41 ` [PATCH v10 7/9] KVM: VMX: Implement and wire get_untagged_addr() for LAM Binbin Wu
2023-08-16 22:01 ` Sean Christopherson [this message]
2023-08-17 9:51 ` Binbin Wu
2023-08-17 14:44 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 8/9] KVM: x86: Untag address for vmexit handlers when LAM applicable Binbin Wu
2023-08-16 21:49 ` Sean Christopherson
2023-08-16 22:10 ` Sean Christopherson
2023-07-19 14:41 ` [PATCH v10 9/9] KVM: x86: Expose LAM feature to userspace VMM Binbin Wu
2023-08-16 21:53 ` Sean Christopherson
2023-08-17 1:59 ` Binbin Wu
2023-08-15 2:05 ` [PATCH v10 0/9] Linear Address Masking (LAM) KVM Enabling Binbin Wu
2023-08-15 23:49 ` Sean Christopherson
2023-08-16 22:25 ` Sean Christopherson
2023-08-17 9:17 ` Binbin Wu
2023-08-18 4:31 ` Binbin Wu
2023-08-18 13:53 ` Sean Christopherson
2023-08-25 14:18 ` Zeng Guang
2023-08-31 20:24 ` Sean Christopherson
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