From: Anshuman Khandual <anshuman.khandual@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: [PATCH V2 4/5] KVM: arm64: Drop check_kvm_target_cpu() based percpu probe
Date: Thu, 12 Aug 2021 10:39:53 +0530 [thread overview]
Message-ID: <1628744994-16623-5-git-send-email-anshuman.khandual@arm.com> (raw)
In-Reply-To: <1628744994-16623-1-git-send-email-anshuman.khandual@arm.com>
kvm_target_cpu() never returns a negative error code, so check_kvm_target()
would never have 'ret' filled with a negative error code. Hence the percpu
probe via check_kvm_target_cpu() does not make sense as its never going to
find an unsupported CPU, forcing kvm_arch_init() to exit early. Hence lets
just drop this percpu probe (and also check_kvm_target_cpu()) altogether.
While here, this also changes kvm_target_cpu() return type to a u32, making
it explicit that an error code will not be returned from this function.
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-kernel@vger.kernel.org
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/kvm/arm.c | 16 +---------------
arch/arm64/kvm/guest.c | 4 ++--
3 files changed, 4 insertions(+), 18 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 41911585ae0c..26bbd84a02de 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -66,7 +66,7 @@ DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
extern unsigned int kvm_sve_max_vl;
int kvm_arm_init_sve(void);
-int __attribute_const__ kvm_target_cpu(void);
+u32 __attribute_const__ kvm_target_cpu(void);
int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 19560e457c11..ee9b1166f330 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1035,7 +1035,7 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
const struct kvm_vcpu_init *init)
{
unsigned int i, ret;
- int phys_target = kvm_target_cpu();
+ u32 phys_target = kvm_target_cpu();
if (init->target != phys_target)
return -EINVAL;
@@ -2010,11 +2010,6 @@ static int finalize_hyp_mode(void)
return 0;
}
-static void check_kvm_target_cpu(void *ret)
-{
- *(int *)ret = kvm_target_cpu();
-}
-
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
{
struct kvm_vcpu *vcpu;
@@ -2074,7 +2069,6 @@ void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
int kvm_arch_init(void *opaque)
{
int err;
- int ret, cpu;
bool in_hyp_mode;
if (!is_hyp_mode_available()) {
@@ -2089,14 +2083,6 @@ int kvm_arch_init(void *opaque)
kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
"Only trusted guests should be used on this system.\n");
- for_each_online_cpu(cpu) {
- smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1);
- if (ret < 0) {
- kvm_err("Error, CPU %d not supported!\n", cpu);
- return -ENODEV;
- }
- }
-
err = kvm_set_ipa_limit();
if (err)
return err;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 1dfb83578277..8ce850fa7b49 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -842,7 +842,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
return 0;
}
-int __attribute_const__ kvm_target_cpu(void)
+u32 __attribute_const__ kvm_target_cpu(void)
{
unsigned long implementor = read_cpuid_implementor();
unsigned long part_number = read_cpuid_part_number();
@@ -874,7 +874,7 @@ int __attribute_const__ kvm_target_cpu(void)
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
{
- int target = kvm_target_cpu();
+ u32 target = kvm_target_cpu();
if (target < 0)
return -ENODEV;
--
2.20.1
next prev parent reply other threads:[~2021-08-12 5:09 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-12 5:09 [PATCH V2 0/5] KVM: arm64: General cleanups Anshuman Khandual
2021-08-12 5:09 ` [PATCH V2 1/5] arm64/mm: Add remaining ID_AA64MMFR0_PARANGE_ macros Anshuman Khandual
2021-08-12 5:09 ` [PATCH V2 2/5] KVM: arm64: Use ARM64_MIN_PARANGE_BITS as the minimum supported IPA Anshuman Khandual
2021-08-12 5:09 ` [PATCH V2 3/5] KVM: arm64: Drop init_common_resources() Anshuman Khandual
2021-08-12 5:09 ` Anshuman Khandual [this message]
2021-08-12 5:09 ` [PATCH V2 5/5] KVM: arm64: Drop unused REQUIRES_VIRT Anshuman Khandual
2021-08-18 8:57 ` [PATCH V2 0/5] KVM: arm64: General cleanups 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=1628744994-16623-5-git-send-email-anshuman.khandual@arm.com \
--to=anshuman.khandual@arm.com \
--cc=alexandru.elisei@arm.com \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.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).