From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: pbonzini@redhat.com, rkrcmar@redhat.com, joro@8bytes.org,
vkuznets@redhat.com, rkagan@virtuozzo.com, graf@amazon.com,
jschoenh@amazon.de, karahmed@amazon.de, rimasluk@amazon.com,
jon.grimm@amd.com,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Subject: [PATCH v5 14/18] kvm: i8254: Deactivate APICv when using in-kernel PIT re-injection mode.
Date: Thu, 14 Nov 2019 14:15:16 -0600 [thread overview]
Message-ID: <1573762520-80328-15-git-send-email-suravee.suthikulpanit@amd.com> (raw)
In-Reply-To: <1573762520-80328-1-git-send-email-suravee.suthikulpanit@amd.com>
AMD SVM AVIC accelerates EOI write and does not trap. This causes
in-kernel PIT re-injection mode to fail since it relies on irq-ack
notifier mechanism. So, APICv is activated only when in-kernel PIT
is in discard mode e.g. w/ qemu option:
-global kvm-pit.lost_tick_policy=discard
Also, introduce APICV_INHIBIT_REASON_PIT_REINJ bit to be used for this
reason.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/i8254.c | 12 ++++++++++++
arch/x86/kvm/svm.c | 11 +++++++++--
3 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4b51222..9cb2d2e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -853,6 +853,7 @@ enum kvm_irqchip_mode {
#define APICV_INHIBIT_REASON_HYPERV 1
#define APICV_INHIBIT_REASON_NESTED 2
#define APICV_INHIBIT_REASON_IRQWIN 3
+#define APICV_INHIBIT_REASON_PIT_REINJ 4
struct kvm_arch {
unsigned long n_used_mmu_pages;
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 4a6dc54..b24c606 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -295,12 +295,24 @@ void kvm_pit_set_reinject(struct kvm_pit *pit, bool reinject)
if (atomic_read(&ps->reinject) == reinject)
return;
+ /*
+ * AMD SVM AVIC accelerates EOI write and does not trap.
+ * This cause in-kernel PIT re-inject mode to fail
+ * since it checks ps->irq_ack before kvm_set_irq()
+ * and relies on the ack notifier to timely queue
+ * the pt->worker work iterm and reinject the missed tick.
+ * So, deactivate APICv when PIT is in reinject mode.
+ */
if (reinject) {
+ kvm_request_apicv_update(kvm, false,
+ APICV_INHIBIT_REASON_PIT_REINJ);
/* The initial state is preserved while ps->reinject == 0. */
kvm_pit_reset_reinject(pit);
kvm_register_irq_ack_notifier(kvm, &ps->irq_ack_notifier);
kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
} else {
+ kvm_request_apicv_update(kvm, true,
+ APICV_INHIBIT_REASON_PIT_REINJ);
kvm_unregister_irq_ack_notifier(kvm, &ps->irq_ack_notifier);
kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
}
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b7883b3..2dfdd7c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1684,7 +1684,13 @@ static int avic_update_access_page(struct kvm *kvm, bool activate)
int ret = 0;
mutex_lock(&kvm->slots_lock);
- if (kvm->arch.apic_access_page_done == activate)
+ /*
+ * During kvm_destroy_vm(), kvm_pit_set_reinject() could trigger
+ * APICv mode change, which update APIC_ACCESS_PAGE_PRIVATE_MEMSLOT
+ * memory region. So, we need to ensure that kvm->mm == current->mm.
+ */
+ if ((kvm->arch.apic_access_page_done == activate) ||
+ (kvm->mm != current->mm))
goto out;
ret = __x86_set_memory_region(kvm,
@@ -7281,7 +7287,8 @@ static bool svm_check_apicv_inhibit_reasons(ulong bit)
ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) |
BIT(APICV_INHIBIT_REASON_HYPERV) |
BIT(APICV_INHIBIT_REASON_NESTED) |
- BIT(APICV_INHIBIT_REASON_IRQWIN);
+ BIT(APICV_INHIBIT_REASON_IRQWIN) |
+ BIT(APICV_INHIBIT_REASON_PIT_REINJ);
return supported & BIT(bit);
}
--
1.8.3.1
next prev parent reply other threads:[~2019-11-14 20:15 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 20:15 [PATCH v5 00/18] kvm: x86: Support AMD SVM AVIC w/ in-kernel irqchip mode Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 01/18] kvm: x86: Modify kvm_x86_ops.get_enable_apicv() to use struct kvm parameter Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 02/18] kvm: lapic: Introduce APICv update helper function Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 03/18] kvm: x86: Introduce APICv inhibit reason bits Suravee Suthikulpanit
2020-01-22 15:51 ` Paolo Bonzini
2019-11-14 20:15 ` [PATCH v5 04/18] kvm: x86: Add support for dynamic APICv Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 05/18] kvm: x86: Add APICv (de)activate request trace points Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 06/18] kvm: x86: svm: Add support to (de)activate posted interrupts Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 07/18] svm: Add support for setup/destroy virutal APIC backing page for AVIC Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 08/18] kvm: x86: Introduce APICv x86 ops for checking APIC inhibit reasons Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 09/18] kvm: x86: Introduce x86 ops hook for pre-update APICv Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 10/18] svm: Add support for dynamic APICv Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 11/18] kvm: x86: hyperv: Use APICv update request interface Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 12/18] svm: Deactivate AVIC when launching guest with nested SVM support Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 13/18] svm: Temporary deactivate AVIC during ExtINT handling Suravee Suthikulpanit
2020-01-22 16:32 ` Paolo Bonzini
2019-11-14 20:15 ` Suravee Suthikulpanit [this message]
2020-02-18 18:51 ` [PATCH v5 14/18] kvm: i8254: Deactivate APICv when using in-kernel PIT re-injection mode Alex Williamson
2020-02-21 2:27 ` Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 15/18] kvm: lapic: Clean up APIC predefined macros Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 16/18] kvm: ioapic: Refactor kvm_ioapic_update_eoi() Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 17/18] kvm: ioapic: Lazy update IOAPIC EOI Suravee Suthikulpanit
2019-11-14 20:15 ` [PATCH v5 18/18] svm: Allow AVIC with in-kernel irqchip mode Suravee Suthikulpanit
2020-01-22 16:06 ` Paolo Bonzini
2020-01-02 10:17 ` [PATCH v5 00/18] kvm: x86: Support AMD SVM AVIC w/ " Suravee Suthikulpanit
2020-01-20 6:16 ` Suravee Suthikulpanit
2020-01-22 16:08 ` Paolo Bonzini
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=1573762520-80328-15-git-send-email-suravee.suthikulpanit@amd.com \
--to=suravee.suthikulpanit@amd.com \
--cc=graf@amazon.com \
--cc=jon.grimm@amd.com \
--cc=joro@8bytes.org \
--cc=jschoenh@amazon.de \
--cc=karahmed@amazon.de \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=rimasluk@amazon.com \
--cc=rkagan@virtuozzo.com \
--cc=rkrcmar@redhat.com \
--cc=vkuznets@redhat.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;
as well as URLs for NNTP newsgroup(s).