kvmarm.lists.cs.columbia.edu archive mirror
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Subject: [PATCH 2/5] KVM: arm64: Refactor filtering of ID registers
Date: Sun, 16 Feb 2020 18:53:21 +0000	[thread overview]
Message-ID: <20200216185324.32596-3-maz@kernel.org> (raw)
In-Reply-To: <20200216185324.32596-1-maz@kernel.org>

Our current ID register filtering is starting to be a mess of if()
statements, and isn't going to get any saner.

Let's turn it into a switch(), which has a chance of being more
readable.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index da82c4b03aab..682fedd7700f 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -9,6 +9,7 @@
  *          Christoffer Dall <c.dall@virtualopensystems.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/bsearch.h>
 #include <linux/kvm_host.h>
 #include <linux/mm.h>
@@ -1070,6 +1071,8 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+#define FEATURE(x)	(GENMASK_ULL(x##_SHIFT + 3, x##_SHIFT))
+
 /* Read a sanitised cpufeature ID register by sys_reg_desc */
 static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 		struct sys_reg_desc const *r, bool raz)
@@ -1078,13 +1081,18 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 			 (u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
 	u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
 
-	if (id == SYS_ID_AA64PFR0_EL1 && !vcpu_has_sve(vcpu)) {
-		val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
-	} else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
-		val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |
-			 (0xfUL << ID_AA64ISAR1_API_SHIFT) |
-			 (0xfUL << ID_AA64ISAR1_GPA_SHIFT) |
-			 (0xfUL << ID_AA64ISAR1_GPI_SHIFT));
+	switch (id) {
+	case SYS_ID_AA64PFR0_EL1:
+		if (!vcpu_has_sve(vcpu))
+			val &= ~FEATURE(ID_AA64PFR0_SVE);
+		break;
+	case SYS_ID_AA64ISAR1_EL1:
+		if (!vcpu_has_ptrauth(vcpu))
+			val &= ~(FEATURE(ID_AA64ISAR1_APA) |
+				 FEATURE(ID_AA64ISAR1_API) |
+				 FEATURE(ID_AA64ISAR1_GPA) |
+				 FEATURE(ID_AA64ISAR1_GPI));
+		break;
 	}
 
 	return val;
-- 
2.20.1

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  parent reply	other threads:[~2020-02-16 18:53 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-16 18:53 [PATCH 0/5] Random debug/PMU fixes for 5.6 Marc Zyngier
2020-02-16 18:53 ` [PATCH 1/5] KVM: arm64: Fix missing RES1 in emulation of DBGBIDR Marc Zyngier
2020-02-18 17:43   ` James Morse
2020-02-18 18:01     ` Robin Murphy
2020-02-18 18:15       ` James Morse
2020-02-16 18:53 ` Marc Zyngier [this message]
2020-02-20 14:12   ` [PATCH 2/5] KVM: arm64: Refactor filtering of ID registers Andre Przywara
2020-02-16 18:53 ` [PATCH 3/5] kvm: arm64: Limit PMU version to ARMv8.1 Marc Zyngier
2020-02-18 17:43   ` James Morse
2020-02-19  9:46     ` Marc Zyngier
2020-02-19 10:18       ` James Morse
2020-02-19 11:14         ` Marc Zyngier
2020-02-16 18:53 ` [PATCH 4/5] KVM: arm64: Limit the debug architecture to ARMv8.0 Marc Zyngier
2020-02-18 17:45   ` James Morse
2020-02-16 18:53 ` [PATCH 5/5] KVM: arm64: Upgrade PMU support to ARMv8.4 Marc Zyngier

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=20200216185324.32596-3-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    /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;
as well as URLs for NNTP newsgroup(s).