0007-xen-hvm-Don-t-skip-MSR_READ-trace-record.patch


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From 97a15007c9606d4c53109754bb21fd593bca589b Mon Sep 17 00:00:00 2001
From: George Dunlap <george.dunlap@cloud.com>
Date: Thu, 8 Aug 2024 13:47:02 +0200
Subject: [PATCH 07/35] xen/hvm: Don't skip MSR_READ trace record

Commit 37f074a3383 ("x86/msr: introduce guest_rdmsr()") introduced a
function to combine the MSR_READ handling between PV and HVM.
Unfortunately, by returning directly, it skipped the trace generation,
leading to gaps in the trace record, as well as xenalyze errors like
this:

hvm_generic_postprocess: d2v0 Strange, exit 7c(VMEXIT_MSR) missing a handler

Replace the `return` with `goto out`.

Fixes: 37f074a3383 ("x86/msr: introduce guest_rdmsr()")
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: bc8a43fff61ae4162a95d84f4e148d6773667cd2
master date: 2024-08-02 08:42:09 +0200
---
 xen/arch/x86/hvm/hvm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 7f4b627b1f..0fe2b85b16 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3557,7 +3557,7 @@ int hvm_msr_read_intercept(unsigned int msr, uint64_t *msr_content)
     fixed_range_base = (uint64_t *)v->arch.hvm.mtrr.fixed_ranges;
 
     if ( (ret = guest_rdmsr(v, msr, msr_content)) != X86EMUL_UNHANDLEABLE )
-        return ret;
+        goto out;
 
     ret = X86EMUL_OKAY;
 
-- 
2.46.1