Test and misc patches

[PULL 06/11] target/ppc/kvm: Replace variable length array in kvmppc_read_hptes()

Thomas Huth posted 11 patches 9 months ago

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Maintainers: "Alex Bennée" <alex.bennee@linaro.org>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Thomas Huth <thuth@redhat.com>, Wainer dos Santos Moschetta <wainersm@redhat.com>, Beraldo Leal <bleal@redhat.com>, Yonggang Luo <luoyonggang@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Laurent Vivier <laurent@vivier.eu>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, John Snow <jsnow@redhat.com>

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[PULL 06/11] target/ppc/kvm: Replace variable length array in kvmppc_read_hptes()

Posted by Thomas Huth 9 months ago

HPTES_PER_GROUP is 8 and HASH_PTE_SIZE_64 is 16, so we don't waste
too many bytes by always allocating the maximum amount of bytes on
the stack here to get rid of the variable length array.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20240221162636.173136-3-thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 target/ppc/kvm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index e7e39c3091..bcf30a5400 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2770,9 +2770,9 @@ void kvmppc_read_hptes(ppc_hash_pte64_t *hptes, hwaddr ptex, int n)
     while (i < n) {
         struct kvm_get_htab_header *hdr;
         int m = n < HPTES_PER_GROUP ? n : HPTES_PER_GROUP;
-        char buf[sizeof(*hdr) + m * HASH_PTE_SIZE_64];
+        char buf[sizeof(*hdr) + HPTES_PER_GROUP * HASH_PTE_SIZE_64];
 
-        rc = read(fd, buf, sizeof(buf));
+        rc = read(fd, buf, sizeof(*hdr) + m * HASH_PTE_SIZE_64);
         if (rc < 0) {
             hw_error("kvmppc_read_hptes: Unable to read HPTEs");
         }
-- 
2.43.2