KVM: nSVM: Propagate SVM_EXIT_CR0_SEL_WRITE correctly for LMSW emulation

KVM: nSVM: Propagate SVM_EXIT_CR0_SEL_WRITE correctly for LMSW emulation

commit 5674a76db0213f9db1e4d08e847ff649b46889c0 upstream.

When emulating L2 instructions, svm_check_intercept() checks whether a
write to CR0 should trigger a synthesized #VMEXIT with
SVM_EXIT_CR0_SEL_WRITE. For MOV-to-CR0, SVM_EXIT_CR0_SEL_WRITE is only
triggered if any bit other than CR0.MP and CR0.TS is updated. However,
according to the APM (24593—Rev.  3.42—March 2024, Table 15-7):

  The LMSW instruction treats the selective CR0-write
  intercept as a non-selective intercept (i.e., it intercepts
  regardless of the value being written).

Skip checking the changed bits for x86_intercept_lmsw and always inject
SVM_EXIT_CR0_SEL_WRITE.

Fixes: cfec82cb7d31 ("KVM: SVM: Add intercept check for emulated cr accesses")
Cc: stable@vger.kernel.org
Reported-by: Matteo Rizzo <matteorizzo@google.com>
Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251024192918.3191141-3-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>