KVM: SVM: Don't rewrite guest ICR on AVIC IPI virtualization failure

KVM: SVM: Don't rewrite guest ICR on AVIC IPI virtualization failure

[ Upstream commit b51818afdc1d3c7cc269e295953685558d3af71c ]

Don't bother rewriting the ICR value into the vAPIC page on an AVIC IPI
virtualization failure, the access is a trap, i.e. the value has already
been written to the vAPIC page.  The one caveat is if hardware left the
BUSY flag set (which appears to happen somewhat arbitrarily), in which
case go through the "nodecode" APIC-write path in order to clear the BUSY
flag.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220204214205.3306634-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Stable-dep-of: 5aede752a839 ("KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target")
Signed-off-by: Sasha Levin <sashal@kernel.org>