From: Dexuan Cui <decui@microsoft.com>
To: ak@linux.intel.com, arnd@arndb.de, bp@alien8.de,
brijesh.singh@amd.com, dan.j.williams@intel.com,
dave.hansen@intel.com, dave.hansen@linux.intel.com,
haiyangz@microsoft.com, hpa@zytor.com, jane.chu@oracle.com,
kirill.shutemov@linux.intel.com, kys@microsoft.com,
linux-hyperv@vger.kernel.org, luto@kernel.org, mingo@redhat.com,
peterz@infradead.org, rostedt@goodmis.org,
sathyanarayanan.kuppuswamy@linux.intel.com, seanjc@google.com,
tglx@linutronix.de, tony.luck@intel.com, wei.liu@kernel.org,
Jason@zx2c4.com, nik.borisov@suse.com, mikelley@microsoft.com
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org, Tianyu.Lan@microsoft.com,
rick.p.edgecombe@intel.com, andavis@redhat.com,
mheslin@redhat.com, vkuznets@redhat.com, xiaoyao.li@intel.com,
Dexuan Cui <decui@microsoft.com>
Subject: [PATCH v3 04/10] x86/hyperv: Fix serial console interrupts for fully enlightened TDX guests
Date: Thu, 24 Aug 2023 01:07:06 -0700 [thread overview]
Message-ID: <20230824080712.30327-5-decui@microsoft.com> (raw)
In-Reply-To: <20230824080712.30327-1-decui@microsoft.com>
When a fully enlightened TDX guest runs on Hyper-V, the UEFI firmware sets
the HW_REDUCED flag and consequently ttyS0 interrupts can't work. Fix the
issue by overriding x86_init.acpi.reduced_hw_early_init().
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
Changes in v2: None
Changes in v3:
Added Tianyu's Reviewed-by.
arch/x86/kernel/cpu/mshyperv.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index ff3d9c5de19c..fe5393d759d3 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -323,6 +323,26 @@ static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
}
#endif
+/*
+ * When a fully enlightened TDX VM runs on Hyper-V, the firmware sets the
+ * HW_REDUCED flag: refer to acpi_tb_create_local_fadt(). Consequently ttyS0
+ * interrupts can't work because request_irq() -> ... -> irq_to_desc() returns
+ * NULL for ttyS0. This happens because mp_config_acpi_legacy_irqs() sees a
+ * nr_legacy_irqs() of 0, so it doesn't initialize the array 'mp_irqs[]', and
+ * later setup_IO_APIC_irqs() -> find_irq_entry() fails to find the legacy irqs
+ * from the array and hence doesn't create the necessary irq description info.
+ *
+ * Clone arch/x86/kernel/acpi/boot.c: acpi_generic_reduced_hw_init() here,
+ * except don't change 'legacy_pic', which keeps its default value
+ * 'default_legacy_pic'. This way, mp_config_acpi_legacy_irqs() sees a non-zero
+ * nr_legacy_irqs() and eventually serial console interrupts works properly.
+ */
+static void __init reduced_hw_init(void)
+{
+ x86_init.timers.timer_init = x86_init_noop;
+ x86_init.irqs.pre_vector_init = x86_init_noop;
+}
+
static void __init ms_hyperv_init_platform(void)
{
int hv_max_functions_eax;
@@ -433,6 +453,8 @@ static void __init ms_hyperv_init_platform(void)
/* Don't trust Hyper-V's TLB-flushing hypercalls. */
ms_hyperv.hints &= ~HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
+
+ x86_init.acpi.reduced_hw_early_init = reduced_hw_init;
}
}
}
--
2.25.1
next prev parent reply other threads:[~2023-08-24 8:11 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-24 8:07 [PATCH v3 00/10] Support TDX guests on Hyper-V (the Hyper-V specific part) Dexuan Cui
2023-08-24 8:07 ` [PATCH v3 01/10] x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests Dexuan Cui
2023-08-24 8:07 ` [PATCH v3 02/10] x86/hyperv: Support hypercalls for fully enlightened " Dexuan Cui
2023-08-24 8:07 ` [PATCH v3 03/10] Drivers: hv: vmbus: Support " Dexuan Cui
2023-08-24 8:07 ` Dexuan Cui [this message]
2023-08-24 8:07 ` [PATCH v3 05/10] Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VM Dexuan Cui
2023-08-24 8:07 ` [PATCH v3 06/10] x86/hyperv: Introduce a global variable hyperv_paravisor_present Dexuan Cui
2023-08-24 14:06 ` Michael Kelley (LINUX)
2023-08-24 14:41 ` Tianyu Lan
2023-08-24 8:07 ` [PATCH v3 07/10] Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor Dexuan Cui
2023-08-24 14:07 ` Michael Kelley (LINUX)
2023-08-24 14:40 ` Tianyu Lan
2023-08-24 8:07 ` [PATCH v3 08/10] x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM " Dexuan Cui
2023-08-24 14:08 ` Michael Kelley (LINUX)
2023-08-24 14:44 ` Tianyu Lan
2023-12-04 15:10 ` Dave Hansen
2024-01-17 2:22 ` Wei Liu
2023-08-24 8:07 ` [PATCH v3 09/10] x86/hyperv: Remove hv_isolation_type_en_snp Dexuan Cui
2023-08-24 14:09 ` Michael Kelley (LINUX)
2023-08-24 14:45 ` Tianyu Lan
2023-08-24 8:07 ` [PATCH v3 10/10] x86/hyperv: Move the code in ivm.c around to avoid unnecessary ifdef's Dexuan Cui
2023-08-24 14:10 ` Michael Kelley (LINUX)
2023-08-24 14:46 ` Tianyu Lan
2023-08-25 0:05 ` [PATCH v3 00/10] Support TDX guests on Hyper-V (the Hyper-V specific part) Wei Liu
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=20230824080712.30327-5-decui@microsoft.com \
--to=decui@microsoft.com \
--cc=Jason@zx2c4.com \
--cc=Tianyu.Lan@microsoft.com \
--cc=ak@linux.intel.com \
--cc=andavis@redhat.com \
--cc=arnd@arndb.de \
--cc=bp@alien8.de \
--cc=brijesh.singh@amd.com \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=haiyangz@microsoft.com \
--cc=hpa@zytor.com \
--cc=jane.chu@oracle.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kys@microsoft.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mheslin@redhat.com \
--cc=mikelley@microsoft.com \
--cc=mingo@redhat.com \
--cc=nik.borisov@suse.com \
--cc=peterz@infradead.org \
--cc=rick.p.edgecombe@intel.com \
--cc=rostedt@goodmis.org \
--cc=sathyanarayanan.kuppuswamy@linux.intel.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=vkuznets@redhat.com \
--cc=wei.liu@kernel.org \
--cc=x86@kernel.org \
--cc=xiaoyao.li@intel.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 read-only IMAP folder(s) and NNTP newsgroup(s).