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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-08 17:45:37 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-08 17:45:37 +0000
commit1c134c659904809d1ca3baf2bb295ca1c7107aee (patch)
treec55c18153612f7df8e54d15aa52db97552d7eb78 /arch/x86/kvm/vmx
parentReleasing progress-linux version 5.10.209-2progress6u1. (diff)
downloadlinux-1c134c659904809d1ca3baf2bb295ca1c7107aee.tar.xz
linux-1c134c659904809d1ca3baf2bb295ca1c7107aee.zip
Merging upstream version 5.10.216.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/kvm/vmx')
-rw-r--r--arch/x86/kvm/vmx/run_flags.h7
-rw-r--r--arch/x86/kvm/vmx/vmenter.S9
-rw-r--r--arch/x86/kvm/vmx/vmx.c12
3 files changed, 19 insertions, 9 deletions
diff --git a/arch/x86/kvm/vmx/run_flags.h b/arch/x86/kvm/vmx/run_flags.h
index edc3f16cc..6a9bfdfbb 100644
--- a/arch/x86/kvm/vmx/run_flags.h
+++ b/arch/x86/kvm/vmx/run_flags.h
@@ -2,7 +2,10 @@
#ifndef __KVM_X86_VMX_RUN_FLAGS_H
#define __KVM_X86_VMX_RUN_FLAGS_H
-#define VMX_RUN_VMRESUME (1 << 0)
-#define VMX_RUN_SAVE_SPEC_CTRL (1 << 1)
+#define VMX_RUN_VMRESUME_SHIFT 0
+#define VMX_RUN_SAVE_SPEC_CTRL_SHIFT 1
+
+#define VMX_RUN_VMRESUME BIT(VMX_RUN_VMRESUME_SHIFT)
+#define VMX_RUN_SAVE_SPEC_CTRL BIT(VMX_RUN_SAVE_SPEC_CTRL_SHIFT)
#endif /* __KVM_X86_VMX_RUN_FLAGS_H */
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 982138beb..7a4b999d5 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -77,7 +77,7 @@ SYM_FUNC_START(__vmx_vcpu_run)
mov (%_ASM_SP), %_ASM_AX
/* Check if vmlaunch or vmresume is needed */
- testb $VMX_RUN_VMRESUME, %bl
+ bt $VMX_RUN_VMRESUME_SHIFT, %bx
/* Load guest registers. Don't clobber flags. */
mov VCPU_RCX(%_ASM_AX), %_ASM_CX
@@ -99,8 +99,11 @@ SYM_FUNC_START(__vmx_vcpu_run)
/* Load guest RAX. This kills the @regs pointer! */
mov VCPU_RAX(%_ASM_AX), %_ASM_AX
- /* Check EFLAGS.ZF from 'testb' above */
- jz .Lvmlaunch
+ /* Clobbers EFLAGS.ZF */
+ CLEAR_CPU_BUFFERS
+
+ /* Check EFLAGS.CF from the VMX_RUN_VMRESUME bit test above. */
+ jnc .Lvmlaunch
/*
* After a successful VMRESUME/VMLAUNCH, control flow "magically"
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2445c6103..3e9bb9ae8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -397,7 +397,8 @@ static __always_inline void vmx_enable_fb_clear(struct vcpu_vmx *vmx)
static void vmx_update_fb_clear_dis(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
{
- vmx->disable_fb_clear = vmx_fb_clear_ctrl_available;
+ vmx->disable_fb_clear = !cpu_feature_enabled(X86_FEATURE_CLEAR_CPU_BUF) &&
+ vmx_fb_clear_ctrl_available;
/*
* If guest will not execute VERW, there is no need to set FB_CLEAR_DIS
@@ -6792,11 +6793,14 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
guest_enter_irqoff();
lockdep_hardirqs_on(CALLER_ADDR0);
- /* L1D Flush includes CPU buffer clear to mitigate MDS */
+ /*
+ * L1D Flush includes CPU buffer clear to mitigate MDS, but VERW
+ * mitigation for MDS is done late in VMentry and is still
+ * executed in spite of L1D Flush. This is because an extra VERW
+ * should not matter much after the big hammer L1D Flush.
+ */
if (static_branch_unlikely(&vmx_l1d_should_flush))
vmx_l1d_flush(vcpu);
- else if (static_branch_unlikely(&mds_user_clear))
- mds_clear_cpu_buffers();
else if (static_branch_unlikely(&mmio_stale_data_clear) &&
kvm_arch_has_assigned_device(vcpu->kvm))
mds_clear_cpu_buffers();