diff options
Diffstat (limited to '0052-x86-vmx-Don-t-spuriously-crash-the-domain-when-INIT-.patch')
| -rw-r--r-- | 0052-x86-vmx-Don-t-spuriously-crash-the-domain-when-INIT-.patch | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/0052-x86-vmx-Don-t-spuriously-crash-the-domain-when-INIT-.patch b/0052-x86-vmx-Don-t-spuriously-crash-the-domain-when-INIT-.patch new file mode 100644 index 0000000..c408fbb --- /dev/null +++ b/0052-x86-vmx-Don-t-spuriously-crash-the-domain-when-INIT-.patch @@ -0,0 +1,51 @@ +From b1022b65de59828d40d9d71cc734a42c1c30c972 Mon Sep 17 00:00:00 2001 +From: Andrew Cooper <andrew.cooper3@citrix.com> +Date: Fri, 31 Mar 2023 08:40:27 +0200 +Subject: [PATCH 52/61] x86/vmx: Don't spuriously crash the domain when INIT is + received + +In VMX operation, the handling of INIT IPIs is changed. Instead of the CPU +resetting, the next VMEntry fails with EXIT_REASON_INIT. From the TXT spec, +the intent of this behaviour is so that an entity which cares can scrub +secrets from RAM before participating in an orderly shutdown. + +Right now, Xen's behaviour is that when an INIT arrives, the HVM VM which +schedules next is killed (citing an unknown VMExit), *and* we ignore the INIT +and continue blindly onwards anyway. + +This patch addresses only the first of these two problems by ignoring the INIT +and continuing without crashing the VM in question. + +The second wants addressing too, just as soon as we've figured out something +better to do... + +Discovered as collateral damage from when an AP triple faults on S3 resume on +Intel TigerLake platforms. + +Link: https://github.com/QubesOS/qubes-issues/issues/7283 +Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> +Reviewed-by: Kevin Tian <kevin.tian@intel.com> +master commit: b1f11273d5a774cc88a3685c96c2e7cf6385e3b6 +master date: 2023-03-24 22:49:58 +0000 +--- + xen/arch/x86/hvm/vmx/vmx.c | 4 ++++ + 1 file changed, 4 insertions(+) + +diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c +index c8a839cd5e..cebe46ef6a 100644 +--- a/xen/arch/x86/hvm/vmx/vmx.c ++++ b/xen/arch/x86/hvm/vmx/vmx.c +@@ -4002,6 +4002,10 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs) + case EXIT_REASON_MCE_DURING_VMENTRY: + do_machine_check(regs); + break; ++ ++ case EXIT_REASON_INIT: ++ printk(XENLOG_ERR "Error: INIT received - ignoring\n"); ++ return; /* Renter the guest without further processing */ + } + + /* Now enable interrupts so it's safe to take locks. */ +-- +2.40.0 + |