From: Brijesh Singh <brijesh.singh@amd.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: brijesh.singh@amd.com, "Borislav Petkov" <bp@suse.de>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, "Tom Lendacky" <thomas.lendacky@amd.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Subject: Re: [PATCH v5 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active
Date: Thu, 6 Sep 2018 15:20:46 -0500 [thread overview]
Message-ID: <9126c92f-ad3b-a5b6-ac44-416405489a7e@amd.com> (raw)
In-Reply-To: <20180906194710.GA16605@linux.intel.com>
On 09/06/2018 02:47 PM, Sean Christopherson wrote:
...
>>
>> Yes, the auxiliary array will dumped into the regular .bss when
>> CONFIG_AMD_MEM_ENCRYPT=n. Typically it will be few k, I am not
>> sure if its worth complicating the code to save those extra memory.
>> Most of the distro's have CONFIG_AMD_MEM_ENCRYPT=y anyways.
>
> I just realized that we'll try to create a bogus array if 'NR_CPUS <=
> HVC_BOOT_ARRAY_SIZE'. A bit ugly, but we could #ifdef away both that
> and CONFIG_AMD_MEM_ENCRYPT=n in a single shot, e.g.:
>
> #if defined(CONFIG_AMD_MEM_ENCRYPT) && NR_CPUS > HVC_BOOT_ARRAY_SIZE
> #define HVC_AUX_ARRAY_SIZE \
> PAGE_ALIGN((NR_CPUS - HVC_BOOT_ARRAY_SIZE) * \
> sizeof(struct pvclock_vsyscall_time_info))
> static struct pvclock_vsyscall_time_info
> hv_clock_aux[HVC_AUX_ARRAY_SIZE] __decrypted __aligned(PAGE_SIZE);
> #endif
>
The HVC_BOOT_ARRAY_SIZE macro uses sizeof(..) and to my understanding
the sizeof operators are not allowed in '#if'. Anyway, I will try to see
if it can be used, if not then I will stick to CONFIG_AMD_MEM_ENCRYPT
check.
-Brijesh
next prev parent reply other threads:[~2018-09-06 20:20 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-06 11:42 [PATCH v5 0/5] x86: Fix SEV guest regression Brijesh Singh
2018-09-06 11:42 ` [PATCH v5 1/5] x86/mm: Restructure sme_encrypt_kernel() Brijesh Singh
2018-09-06 11:42 ` [PATCH v5 2/5] x86/mm: fix sme_populate_pgd() to update page flags Brijesh Singh
2018-09-06 11:43 ` [PATCH v5 3/5] x86/mm: add .data..decrypted section to hold shared variables Brijesh Singh
2018-09-06 11:43 ` [PATCH v5 4/5] x86/kvm: use __decrypted attribute in " Brijesh Singh
2018-09-06 11:43 ` [PATCH v5 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active Brijesh Singh
2018-09-06 12:24 ` Borislav Petkov
2018-09-06 13:50 ` Sean Christopherson
2018-09-06 14:18 ` Sean Christopherson
2018-09-06 14:44 ` Borislav Petkov
2018-09-06 18:37 ` Brijesh Singh
2018-09-06 18:47 ` Sean Christopherson
2018-09-06 19:24 ` Brijesh Singh
2018-09-06 19:46 ` Brijesh Singh
2018-09-06 19:47 ` Sean Christopherson
2018-09-06 20:20 ` Brijesh Singh [this message]
2018-09-06 20:39 ` Sean Christopherson
2018-09-06 21:56 ` Brijesh Singh
2018-09-06 14:43 ` Borislav Petkov
2018-09-06 14:56 ` Sean Christopherson
2018-09-06 15:19 ` Borislav Petkov
2018-09-06 15:54 ` Sean Christopherson
2018-09-06 18:33 ` Borislav Petkov
2018-09-06 18:43 ` Brijesh Singh
2018-09-06 18:45 ` Sean Christopherson
2018-09-06 19:03 ` Borislav Petkov
2018-09-06 17:50 ` Brijesh Singh
2018-09-06 14:07 ` Sean Christopherson
2018-09-06 18:50 ` Brijesh Singh
2018-09-07 3:57 ` Brijesh Singh
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