From: David Laight <David.Laight@ACULAB.COM>
To: 'Maxim Levitsky' <mlevitsk@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Cc: "seanjc@google.com" <seanjc@google.com>
Subject: RE: [PATCH v3 6/6] KVM: x86: allow defining return-0 static calls
Date: Thu, 17 Mar 2022 22:30:39 +0000 [thread overview]
Message-ID: <a63028d4ece24040b382ab2bba50bcad@AcuMS.aculab.com> (raw)
In-Reply-To: <3bbe3f8717cdf122f909a48e117dab6c09d8e0c8.camel@redhat.com>
> I guess something with returning u64 made 32 compiler unhappy.
>
> I suspect that __static_call_return0 returns long, which means it returns
> 32 bit value on 32 bit system.
>
> Maybe we can make it return u64. I don't know if that will break something else though.
32 bit system will return a 64bit value in %edx:%eax.
Since %rdx is a scratch register (caller saved) it is fine.
Is __statc_call_return0() ever used to return a NULL pointer?
ISTR some ABI (maybe m68k ones) that returned pointers and
integers in different registers.
Plausibly that was only 35 years ago.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-03-17 22:30 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-17 18:08 [PATCH v3 0/6] kvm: x86: better handling of optional kvm_x86_ops Paolo Bonzini
2022-02-17 18:08 ` [PATCH v3 1/6] KVM: x86: return 1 unconditionally for availability of KVM_CAP_VAPIC Paolo Bonzini
2022-02-18 15:44 ` Sean Christopherson
2022-02-23 13:21 ` Maxim Levitsky
2022-02-17 18:08 ` [PATCH v3 2/6] KVM: x86: use static_call_cond for optional callbacks Paolo Bonzini
2022-02-18 15:46 ` Sean Christopherson
2022-02-17 18:08 ` [PATCH v3 3/6] KVM: x86: remove KVM_X86_OP_NULL and mark optional kvm_x86_ops Paolo Bonzini
2022-02-18 15:52 ` Sean Christopherson
2022-02-17 18:08 ` [PATCH v3 4/6] KVM: x86: warn on incorrectly NULL members of kvm_x86_ops Paolo Bonzini
2022-02-18 16:18 ` Sean Christopherson
2022-02-17 18:08 ` [PATCH v3 5/6] KVM: x86: make several AVIC callbacks optional Paolo Bonzini
2022-02-18 16:23 ` Sean Christopherson
2022-02-18 17:17 ` Paolo Bonzini
2022-02-18 17:37 ` Sean Christopherson
2022-02-18 17:41 ` Paolo Bonzini
2022-02-17 18:08 ` [PATCH v3 6/6] KVM: x86: allow defining return-0 static calls Paolo Bonzini
2022-02-18 16:29 ` Sean Christopherson
2022-02-18 17:20 ` Paolo Bonzini
2022-02-18 17:33 ` Sean Christopherson
2022-03-17 17:43 ` Maxim Levitsky
2022-03-17 22:30 ` David Laight [this message]
2022-03-18 16:29 ` Paolo Bonzini
2022-03-18 17:28 ` Peter Zijlstra
2022-03-18 17:47 ` Peter Zijlstra
2022-03-18 18:02 ` Peter Zijlstra
2022-03-18 23:03 ` David Laight
2022-03-20 13:58 ` Maxim Levitsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=a63028d4ece24040b382ab2bba50bcad@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mlevitsk@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox