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Reply-To: Wei Zhang <zhanwei@google.com>
Date:   Tue, 12 Apr 2022 19:58:46 +0000
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Subject: [PATCH 2/2] KVM: x86: illustrative example for sending guest _stext
 with a hypercall
From:   Wei Zhang <zhanwei@google.com>
Cc:     Wei Zhang <zhanwei@google.com>,
        Suleiman Souhlal <suleiman@google.com>,
        Sangwhan Moon <sxm@google.com>, Ingo Molnar <mingo@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
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A guest could send its _stext with the newly added hypercall. The
statistics collected afterwards will be correct in the kernel.

Signed-off-by: Wei Zhang <zhanwei@google.com>
---
 arch/x86/kernel/setup.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c95b9ac5a457..ee8c4fd4efe9 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -24,6 +24,7 @@
 #include <linux/static_call.h>
 #include <linux/swiotlb.h>
 
+#include <uapi/linux/kvm_para.h>
 #include <uapi/linux/mount.h>
 
 #include <xen/xen.h>
@@ -1241,6 +1242,11 @@ void __init setup_arch(char **cmdline_p)
 #endif
 
 	unwind_init();
+
+	/*
+	 * Send the _stext to the host kernel.
+	 */
+	kvm_hypercall1(KVM_HC_GUEST_STEXT, (unsigned long)_stext);
 }
 
 #ifdef CONFIG_X86_32
-- 
2.35.1.1178.g4f1659d476-goog