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Thu, 8 Apr 2021 10:24:08 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1lURpW-006HDf-1m; Thu, 08 Apr 2021 11:24:06 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 08 Apr 2021 11:24:05 +0100 From: Marc Zyngier To: Pavel Tatashin Cc: jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, vladimir.murzin@arm.com, matthias.bgg@gmail.com, linux-mm@kvack.org, mark.rutland@arm.com, steve.capper@arm.com, rfontana@redhat.com, tglx@linutronix.de, selindag@gmail.com, tyhicks@linux.microsoft.com, kernelfans@gmail.com Subject: Re: [PATCH v13 03/18] arm64: hyp-stub: Move el1_sync into the vectors In-Reply-To: <20210408040537.2703241-4-pasha.tatashin@soleen.com> References: <20210408040537.2703241-1-pasha.tatashin@soleen.com> <20210408040537.2703241-4-pasha.tatashin@soleen.com> User-Agent: Roundcube Webmail/1.4.11 Message-ID: <480272f8fb3e46d24a0ee1418fb85809@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, vladimir.murzin@arm.com, matthias.bgg@gmail.com, linux-mm@kvack.org, mark.rutland@arm.com, steve.capper@arm.com, rfontana@redhat.com, tglx@linutronix.de, selindag@gmail.com, tyhicks@linux.microsoft.com, kernelfans@gmail.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-Rspamd-Queue-Id: CB386132 X-Stat-Signature: mndewje4w515nzjpp131wfyzys74b73p X-Rspamd-Server: rspam02 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: none/none X-HE-Tag: 1617877445-323181 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2021-04-08 05:05, Pavel Tatashin wrote: > From: James Morse > > The hyp-stub's el1_sync code doesn't do very much, this can easily fit > in the vectors. > > With this, all of the hyp-stubs behaviour is contained in its vectors. > This lets kexec and hibernate copy the hyp-stub when they need its > behaviour, instead of re-implementing it. > > Signed-off-by: James Morse > > [Fixed merging issues] That's a pretty odd fix IMO. > > Signed-off-by: Pavel Tatashin > --- > arch/arm64/kernel/hyp-stub.S | 59 ++++++++++++++++++------------------ > 1 file changed, 29 insertions(+), 30 deletions(-) > > diff --git a/arch/arm64/kernel/hyp-stub.S > b/arch/arm64/kernel/hyp-stub.S > index ff329c5c074d..d1a73d0f74e0 100644 > --- a/arch/arm64/kernel/hyp-stub.S > +++ b/arch/arm64/kernel/hyp-stub.S > @@ -21,6 +21,34 @@ SYM_CODE_START_LOCAL(\label) > .align 7 > b \label > SYM_CODE_END(\label) > +.endm > + > +.macro hyp_stub_el1_sync > +SYM_CODE_START_LOCAL(hyp_stub_el1_sync) > + .align 7 > + cmp x0, #HVC_SET_VECTORS > + b.ne 2f > + msr vbar_el2, x1 > + b 9f > + > +2: cmp x0, #HVC_SOFT_RESTART > + b.ne 3f > + mov x0, x2 > + mov x2, x4 > + mov x4, x1 > + mov x1, x3 > + br x4 // no return > + > +3: cmp x0, #HVC_RESET_VECTORS > + beq 9f // Nothing to reset! > + > + /* Someone called kvm_call_hyp() against the hyp-stub... */ > + mov_q x0, HVC_STUB_ERR > + eret > + > +9: mov x0, xzr > + eret > +SYM_CODE_END(hyp_stub_el1_sync) You said you tested this on a TX2. I guess you don't care whether it runs VHE or not... M. > .endm > > .text > @@ -39,7 +67,7 @@ SYM_CODE_START(__hyp_stub_vectors) > invalid_vector hyp_stub_el2h_fiq_invalid // FIQ EL2h > invalid_vector hyp_stub_el2h_error_invalid // Error EL2h > > - ventry el1_sync // Synchronous 64-bit EL1 > + hyp_stub_el1_sync // Synchronous 64-bit EL1 > invalid_vector hyp_stub_el1_irq_invalid // IRQ 64-bit EL1 > invalid_vector hyp_stub_el1_fiq_invalid // FIQ 64-bit EL1 > invalid_vector hyp_stub_el1_error_invalid // Error 64-bit EL1 > @@ -55,35 +83,6 @@ SYM_CODE_END(__hyp_stub_vectors) > # Check the __hyp_stub_vectors didn't overflow > .org . - (__hyp_stub_vectors_end - __hyp_stub_vectors) + SZ_2K > > - > -SYM_CODE_START_LOCAL(el1_sync) > - cmp x0, #HVC_SET_VECTORS > - b.ne 1f > - msr vbar_el2, x1 > - b 9f > - > -1: cmp x0, #HVC_VHE_RESTART > - b.eq mutate_to_vhe > - > -2: cmp x0, #HVC_SOFT_RESTART > - b.ne 3f > - mov x0, x2 > - mov x2, x4 > - mov x4, x1 > - mov x1, x3 > - br x4 // no return > - > -3: cmp x0, #HVC_RESET_VECTORS > - beq 9f // Nothing to reset! > - > - /* Someone called kvm_call_hyp() against the hyp-stub... */ > - mov_q x0, HVC_STUB_ERR > - eret > - > -9: mov x0, xzr > - eret > -SYM_CODE_END(el1_sync) > - > // nVHE? No way! Give me the real thing! > SYM_CODE_START_LOCAL(mutate_to_vhe) > // Sanity check: MMU *must* be off -- Jazz is not dead. It just smells funny...