[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[PATCH 3/5] VMX: don't run with CR4.VMXE set when VMX could not be enabled


  • To: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: Jan Beulich <jbeulich@xxxxxxxx>
  • Date: Thu, 16 Nov 2023 14:32:07 +0100
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=BH2ili1cHCQHt6/Qmlk6IQSHtN0pbcv6mxMT7/SbihE=; b=grbl9di9HveNzE8N7YuO73ibRPm0rEx2hHmQU/HrMxvUrvtv+b2XSYo31HZU/p/vayKyaCA6qJas+4nfrNAtl39XwPqAK49Z6mEwpaAEl8hf1vb8V5f7VvtN8OwzB2F5FawI8RKV3NMnPmM2CcAnwoiWK5uNf5zJkEH3axsghod7b91VkJ+Ik+FUzEwSnqgQt+eCwBGm/M3dFWFFUGYgFLuWu7fQI8lSehTx1lyKCnyMeg6o6bQMNlRn5LT1tr+nwMMjPZFT7/5ZRh9JujsO2SJZVI97R2x/g71qzqFrrFIi7Yz8ZjuEwTOLSzZR9Pr4vCwUSuXlcyBGxys49zr8ug==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=SMJyj/DHv/ISSgs5UP8EAZ9C8xzUxb1yBeemLwloN1gJGENNb+QPGWCPbY1JjajNe1GndZPqE25+yQKo7jwBskSy6fIFbHedE/TMdPQ1JFLwPec2rPPKw23d/O9YWwotJg6T/gF/3wrv/h2hkdTk3Ff/zt24rcYdQFYysl/2wpjeVZIRheOv0nORIZC/aDykuAqsxrcMrI4x3a4qED5AZDmwmF7A8wwCtiWHysOaR3YvfpxS2isUzLmOHHBgv+sS/RwwyS0PyNc82drcVrFarPOV0mOBy1MJcxnjHizZSayhBaDlv/Njr9m4SyGf6Ex5qW+tfA8YBtgHDwYsovROuA==
  • Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
  • Autocrypt: addr=jbeulich@xxxxxxxx; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL
  • Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>, Kevin Tian <kevin.tian@xxxxxxxxx>, Jun Nakajima <jun.nakajima@xxxxxxxxx>
  • Delivery-date: Thu, 16 Nov 2023 13:32:12 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

While generally benign, doing so is still at best misleading.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Using set_in_cr4() seems favorable over updating mmu_cr4_features
despite the resulting redundant CR4 update. But I certainly could be
talked into going the alternative route.

--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2959,7 +2959,7 @@ static bool __init has_if_pschange_mc(vo
 
 const struct hvm_function_table * __init start_vmx(void)
 {
-    set_in_cr4(X86_CR4_VMXE);
+    write_cr4(read_cr4() | X86_CR4_VMXE);
 
     if ( vmx_vmcs_init() )
     {
@@ -2967,6 +2967,9 @@ const struct hvm_function_table * __init
         return NULL;
     }
 
+    /* Arrange for APs to have CR4.VMXE set early on. */
+    set_in_cr4(X86_CR4_VMXE);
+
     vmx_function_table.singlestep_supported = cpu_has_monitor_trap_flag;
 
     if ( cpu_has_vmx_dt_exiting )




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.