Merge tag 'x86_urgent_for_v6.1_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - ioremap: mask out the bits which are not part of the physical address
   *after* the size computation is done to prevent any hypothetical
   ioremap failures

 - Change the MSR save/restore functionality during suspend to rely on
   flags denoting that the related MSRs are actually supported vs
   reading them and assuming they are (an Atom one allows reading but
   not writing, thus breaking this scheme at resume time)

 - prevent IV reuse in the AES-GCM communication scheme between SNP
   guests and the AMD secure processor

* tag 'x86_urgent_for_v6.1_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioremap: Fix page aligned size calculation in __ioremap_caller()
  x86/pm: Add enumeration check before spec MSRs save/restore setup
  x86/tsx: Add a feature bit for TSX control MSR support
  virt/sev-guest: Prevent IV reuse in the SNP guest driver

1 files changed, 17 insertions, 21 deletions

diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c
index ec7bbac3a9f2..8009c8346d8f 100644
--- a/arch/x86/kernel/cpu/tsx.c
+++ b/arch/x86/kernel/cpu/tsx.c
@@ -58,24 +58,6 @@ static void tsx_enable(void)
 	wrmsrl(MSR_IA32_TSX_CTRL, tsx);
 }
 
-static bool tsx_ctrl_is_supported(void)
-{
-	u64 ia32_cap = x86_read_arch_cap_msr();
-
-	/*
-	 * TSX is controlled via MSR_IA32_TSX_CTRL.  However, support for this
-	 * MSR is enumerated by ARCH_CAP_TSX_MSR bit in MSR_IA32_ARCH_CAPABILITIES.
-	 *
-	 * TSX control (aka MSR_IA32_TSX_CTRL) is only available after a
-	 * microcode update on CPUs that have their MSR_IA32_ARCH_CAPABILITIES
-	 * bit MDS_NO=1. CPUs with MDS_NO=0 are not planned to get
-	 * MSR_IA32_TSX_CTRL support even after a microcode update. Thus,
-	 * tsx= cmdline requests will do nothing on CPUs without
-	 * MSR_IA32_TSX_CTRL support.
-	 */
-	return !!(ia32_cap & ARCH_CAP_TSX_CTRL_MSR);
-}
-
 static enum tsx_ctrl_states x86_get_tsx_auto_mode(void)
 {
 	if (boot_cpu_has_bug(X86_BUG_TAA))
@@ -135,7 +117,7 @@ static void tsx_clear_cpuid(void)
 		rdmsrl(MSR_TSX_FORCE_ABORT, msr);
 		msr |= MSR_TFA_TSX_CPUID_CLEAR;
 		wrmsrl(MSR_TSX_FORCE_ABORT, msr);
-	} else if (tsx_ctrl_is_supported()) {
+	} else if (cpu_feature_enabled(X86_FEATURE_MSR_TSX_CTRL)) {
 		rdmsrl(MSR_IA32_TSX_CTRL, msr);
 		msr |= TSX_CTRL_CPUID_CLEAR;
 		wrmsrl(MSR_IA32_TSX_CTRL, msr);
@@ -158,7 +140,8 @@ static void tsx_dev_mode_disable(void)
 	u64 mcu_opt_ctrl;
 
 	/* Check if RTM_ALLOW exists */
-	if (!boot_cpu_has_bug(X86_BUG_TAA) || !tsx_ctrl_is_supported() ||
+	if (!boot_cpu_has_bug(X86_BUG_TAA) ||
+	    !cpu_feature_enabled(X86_FEATURE_MSR_TSX_CTRL) ||
 	    !cpu_feature_enabled(X86_FEATURE_SRBDS_CTRL))
 		return;
 
@@ -191,7 +174,20 @@ void __init tsx_init(void)
 		return;
 	}
 
-	if (!tsx_ctrl_is_supported()) {
+	/*
+	 * TSX is controlled via MSR_IA32_TSX_CTRL.  However, support for this
+	 * MSR is enumerated by ARCH_CAP_TSX_MSR bit in MSR_IA32_ARCH_CAPABILITIES.
+	 *
+	 * TSX control (aka MSR_IA32_TSX_CTRL) is only available after a
+	 * microcode update on CPUs that have their MSR_IA32_ARCH_CAPABILITIES
+	 * bit MDS_NO=1. CPUs with MDS_NO=0 are not planned to get
+	 * MSR_IA32_TSX_CTRL support even after a microcode update. Thus,
+	 * tsx= cmdline requests will do nothing on CPUs without
+	 * MSR_IA32_TSX_CTRL support.
+	 */
+	if (x86_read_arch_cap_msr() & ARCH_CAP_TSX_CTRL_MSR) {
+		setup_force_cpu_cap(X86_FEATURE_MSR_TSX_CTRL);
+	} else {
 		tsx_ctrl_state = TSX_CTRL_NOT_SUPPORTED;
 		return;
 	}