linux-kernel - [PATCH 3/4] KVM: SVM: Adjust MMIO masks (for caching) before doing SEV(-ES) setup

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Message-Id: <20220728221759.3492539-4-seanjc@google.com>
Date:   Thu, 28 Jul 2022 22:17:58 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Michael Roth <michael.roth@....com>,
        Tom Lendacky <thomas.lendacky@....com>
Subject: [PATCH 3/4] KVM: SVM: Adjust MMIO masks (for caching) before doing
 SEV(-ES) setup

Adjust KVM's MMIO masks to account for the C-bit location prior to doing
SEV(-ES) setup.  A future patch will consume enable_mmio caching during
SEV setup as SEV-ES _requires_ MMIO caching, i.e. KVM needs to disallow
SEV-ES if MMIO caching is disabled.

Cc: stable@...r.kernel.org
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/svm.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index aef63aae922d..62e89db83bc1 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -5034,13 +5034,16 @@ static __init int svm_hardware_setup(void)
 	/* Setup shadow_me_value and shadow_me_mask */
 	kvm_mmu_set_me_spte_mask(sme_me_mask, sme_me_mask);
 
-	/* Note, SEV setup consumes npt_enabled. */
+	svm_adjust_mmio_mask();
+
+	/*
+	 * Note, SEV setup consumes npt_enabled and enable_mmio_caching (which
+	 * may be modified by svm_adjust_mmio_mask()).
+	 */
 	sev_hardware_setup();
 
 	svm_hv_hardware_setup();
 
-	svm_adjust_mmio_mask();
-
 	for_each_possible_cpu(cpu) {
 		r = svm_cpu_init(cpu);
 		if (r)
-- 
2.37.1.455.g008518b4e5-goog