From: Marc Zyngier <marc.zyngier@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Christoffer Dall <christoffer.dall@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
kvmarm@lists.cs.columbia.edu
Subject: [PATCH v2 06/21] arm64: KVM: VHE: Patch out use of HVC
Date: Mon, 25 Jan 2016 15:53:40 +0000 [thread overview]
Message-ID: <1453737235-16522-7-git-send-email-marc.zyngier@arm.com> (raw)
In-Reply-To: <1453737235-16522-1-git-send-email-marc.zyngier@arm.com>
With VHE, the host never issues an HVC instruction to get into the
KVM code, as we can simply branch there.
Use runtime code patching to simplify things a bit.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/hyp.S | 7 +++++++
arch/arm64/kvm/hyp/hyp-entry.S | 38 +++++++++++++++++++++++++++++---------
2 files changed, 36 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 0ccdcbb..0689a74 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -17,7 +17,9 @@
#include <linux/linkage.h>
+#include <asm/alternative.h>
#include <asm/assembler.h>
+#include <asm/cpufeature.h>
/*
* u64 kvm_call_hyp(void *hypfn, ...);
@@ -38,6 +40,11 @@
* arch/arm64/kernel/hyp_stub.S.
*/
ENTRY(kvm_call_hyp)
+alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
hvc #0
ret
+alternative_else
+ b __vhe_hyp_call
+ nop
+alternative_endif
ENDPROC(kvm_call_hyp)
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 93e8d983..9e0683f 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -38,6 +38,32 @@
ldp x0, x1, [sp], #16
.endm
+.macro do_el2_call
+ /*
+ * Shuffle the parameters before calling the function
+ * pointed to in x0. Assumes parameters in x[1,2,3].
+ */
+ stp lr, xzr, [sp, #-16]!
+ mov lr, x0
+ mov x0, x1
+ mov x1, x2
+ mov x2, x3
+ blr lr
+ ldp lr, xzr, [sp], #16
+.endm
+
+ENTRY(__vhe_hyp_call)
+ do_el2_call
+ /*
+ * We used to rely on having an exception return to get
+ * an implicit isb. In the E2H case, we don't have it anymore.
+ * rather than changing all the leaf functions, just do it here
+ * before returning to the rest of the kernel.
+ */
+ isb
+ ret
+ENDPROC(__vhe_hyp_call)
+
el1_sync: // Guest trapped into EL2
save_x0_to_x3
@@ -58,19 +84,13 @@ el1_sync: // Guest trapped into EL2
mrs x0, vbar_el2
b 2f
-1: stp lr, xzr, [sp, #-16]!
-
+1:
/*
- * Compute the function address in EL2, and shuffle the parameters.
+ * Perform the EL2 call
*/
kern_hyp_va x0
- mov lr, x0
- mov x0, x1
- mov x1, x2
- mov x2, x3
- blr lr
+ do_el2_call
- ldp lr, xzr, [sp], #16
2: eret
el1_trap:
--
2.1.4
next prev parent reply other threads:[~2016-01-25 15:54 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-25 15:53 [PATCH v2 00/21] arm64: Virtualization Host Extension support Marc Zyngier
2016-01-25 15:53 ` [PATCH v2 01/21] arm/arm64: Add new is_kernel_in_hyp_mode predicate Marc Zyngier
2016-02-01 13:59 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 02/21] arm64: Allow the arch timer to use the HYP timer Marc Zyngier
2016-02-01 12:29 ` Christoffer Dall
2016-02-01 13:42 ` Marc Zyngier
2016-02-01 15:37 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 03/21] arm64: Add ARM64_HAS_VIRT_HOST_EXTN feature Marc Zyngier
2016-02-01 13:59 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 04/21] arm64: KVM: Skip HYP setup when already running in HYP Marc Zyngier
2016-02-01 13:59 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 05/21] arm64: KVM: VHE: Turn VTCR_EL2 setup into a reusable macro Marc Zyngier
2016-02-01 13:13 ` Christoffer Dall
2016-02-01 14:21 ` Marc Zyngier
2016-02-01 15:38 ` Christoffer Dall
2016-01-25 15:53 ` Marc Zyngier [this message]
2016-02-01 13:16 ` [PATCH v2 06/21] arm64: KVM: VHE: Patch out use of HVC Christoffer Dall
2016-02-01 13:34 ` Marc Zyngier
2016-02-01 15:36 ` Catalin Marinas
2016-02-01 16:20 ` Marc Zyngier
2016-02-01 17:08 ` Ard Biesheuvel
2016-02-01 17:28 ` Marc Zyngier
2016-02-02 15:42 ` Christoffer Dall
2016-02-01 15:39 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 07/21] arm64: KVM: VHE: Patch out kern_hyp_va Marc Zyngier
2016-02-01 13:20 ` Christoffer Dall
2016-02-01 13:38 ` Marc Zyngier
2016-02-01 15:40 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 08/21] arm64: KVM: VHE: Introduce unified system register accessors Marc Zyngier
2016-02-01 13:47 ` Christoffer Dall
2016-02-01 14:04 ` Marc Zyngier
2016-02-01 15:43 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 09/21] arm64: KVM: VHE: Differenciate host/guest sysreg save/restore Marc Zyngier
2016-02-01 13:59 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 10/21] arm64: KVM: VHE: Split save/restore of sysregs shared between EL1 and EL2 Marc Zyngier
2016-02-01 13:54 ` Christoffer Dall
2016-02-02 9:46 ` Marc Zyngier
2016-02-02 15:46 ` Christoffer Dall
2016-02-02 16:19 ` Marc Zyngier
2016-02-02 20:07 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 11/21] arm64: KVM: VHE: Use unified system register accessors Marc Zyngier
2016-02-01 13:59 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 12/21] arm64: KVM: VHE: Enable minimal sysreg save/restore Marc Zyngier
2016-02-01 14:02 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 13/21] arm64: KVM: VHE: Make __fpsimd_enabled VHE aware Marc Zyngier
2016-02-01 14:17 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 14/21] arm64: KVM: VHE: Implement VHE activate/deactivate_traps Marc Zyngier
2016-02-01 14:20 ` Christoffer Dall
2016-02-02 11:27 ` Marc Zyngier
2016-01-25 15:53 ` [PATCH v2 15/21] arm64: KVM: VHE: Use unified sysreg accessors for timer Marc Zyngier
2016-02-01 14:23 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 16/21] arm64: KVM: VHE: Add fpsimd enabling on guest access Marc Zyngier
2016-02-01 14:24 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 17/21] arm64: KVM: VHE: Add alternative panic handling Marc Zyngier
2016-02-01 14:26 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 18/21] arm64: KVM: Introduce hyp_alternate_value helper Marc Zyngier
2016-02-01 14:41 ` Christoffer Dall
2016-02-02 13:42 ` Marc Zyngier
2016-02-02 15:47 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 19/21] arm64: KVM: Move most of the fault decoding to C Marc Zyngier
2016-02-01 15:21 ` Christoffer Dall
2016-02-02 14:24 ` Marc Zyngier
2016-02-02 15:50 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode Marc Zyngier
2016-01-26 14:04 ` Suzuki K. Poulose
2016-01-26 14:30 ` Suzuki K. Poulose
2016-02-01 15:26 ` Christoffer Dall
2016-01-25 15:53 ` [PATCH v2 21/21] arm64: Panic when VHE and non VHE CPUs coexist Marc Zyngier
2016-01-26 14:25 ` Suzuki K. Poulose
2016-01-26 14:34 ` Marc Zyngier
2016-02-01 15:36 ` Christoffer Dall
2016-02-02 15:32 ` Marc Zyngier
2016-02-03 8:49 ` Christoffer Dall
2016-02-03 17:45 ` Marc Zyngier
2016-02-03 19:12 ` Christoffer Dall
2016-01-25 16:15 ` [PATCH v2 00/21] arm64: Virtualization Host Extension support Arnd Bergmann
2016-01-25 16:23 ` Marc Zyngier
2016-01-25 16:26 ` Arnd Bergmann
2016-01-25 16:26 ` Will Deacon
2016-01-25 16:37 ` Marc Zyngier
2016-01-25 16:44 ` Will Deacon
2016-01-25 19:16 ` Marc Zyngier
2016-02-01 16:25 ` Christoffer Dall
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=1453737235-16522-7-git-send-email-marc.zyngier@arm.com \
--to=marc.zyngier@arm.com \
--cc=catalin.marinas@arm.com \
--cc=christoffer.dall@linaro.org \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=will.deacon@arm.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
all inboxes | Powered by JetHome®