linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kuppuswamy Sathyanarayanan  <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>
Cc: Peter H Anvin <hpa@zytor.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Sean Christopherson <seanjc@google.com>,
	Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v4 4/5] x86/tdx: Forcefully disable legacy PIC for TDX guests
Date: Wed,  4 Aug 2021 12:27:27 -0700	[thread overview]
Message-ID: <20210804192729.2902472-5-sathyanarayanan.kuppuswamy@linux.intel.com> (raw)
In-Reply-To: <20210804192729.2902472-1-sathyanarayanan.kuppuswamy@linux.intel.com>

From: Sean Christopherson <sean.j.christopherson@intel.com>

Disable the legacy PIC (8259) for TDX guests as the PIC cannot be
supported by the VMM. TDX Module does not allow direct IRQ injection,
and using posted interrupt style delivery requires the guest to EOI
the IRQ, which diverges from the legacy PIC behavior.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---

Changes since v3:
 * None.

 arch/x86/kernel/tdx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c
index 1b6ed482c6b6..0c24439774b4 100644
--- a/arch/x86/kernel/tdx.c
+++ b/arch/x86/kernel/tdx.c
@@ -8,6 +8,7 @@
 #include <linux/cpuhotplug.h>
 
 #include <asm/tdx.h>
+#include <asm/i8259.h>
 #include <asm/vmx.h>
 #include <asm/insn.h>
 #include <asm/insn-eval.h>
@@ -455,6 +456,8 @@ void __init tdx_early_init(void)
 	pv_ops.irq.safe_halt = tdg_safe_halt;
 	pv_ops.irq.halt = tdg_halt;
 
+	legacy_pic = &null_legacy_pic;
+
 	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "tdg:cpu_hotplug",
 			  NULL, tdg_cpu_offline_prepare);
 
-- 
2.25.1


  parent reply	other threads:[~2021-08-04 19:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 19:27 [PATCH v4 0/5] Add TDX Guest Support (boot fixes) Kuppuswamy Sathyanarayanan
2021-08-04 19:27 ` [PATCH v4 1/5] x86/boot: Add a trampoline for APs booting in 64-bit mode Kuppuswamy Sathyanarayanan
2021-08-04 19:27 ` [PATCH v4 2/5] x86/boot: Avoid #VE during boot for TDX platforms Kuppuswamy Sathyanarayanan
2021-08-04 19:27 ` [PATCH v4 3/5] x86/topology: Disable CPU online/offline control for TDX guest Kuppuswamy Sathyanarayanan
2021-08-04 19:27 ` Kuppuswamy Sathyanarayanan [this message]
2021-08-04 19:27 ` [PATCH v4 5/5] x86: Skip WBINVD instruction for VM guest Kuppuswamy Sathyanarayanan

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=20210804192729.2902472-5-sathyanarayanan.kuppuswamy@linux.intel.com \
    --to=sathyanarayanan.kuppuswamy@linux.intel.com \
    --cc=ak@linux.intel.com \
    --cc=bp@alien8.de \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=hpa@zytor.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=knsathya@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=seanjc@google.com \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=x86@kernel.org \
    --subject='Re: [PATCH v4 4/5] x86/tdx: Forcefully disable legacy PIC for TDX guests' \
    /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

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox