community/qemu: backport fixes for loongarch64

ref:
https://gitlab.com/qemu-project/qemu/-/issues/2504
a4ad4a9d98

community/qemu/APKBUILD

@@ -4,7 +4,7 @@
 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=qemu
 pkgver=9.0.2
-pkgrel=0
+pkgrel=1
 pkgdesc="QEMU is a generic machine emulator and virtualizer"
 url="https://qemu.org/"
 arch="all"
@@ -219,6 +219,7 @@ source="https://download.qemu.org/qemu-$pkgver.tar.xz
 	musl-initialise-msghdr.patch
 	fix-strerrorname_np.patch
 	liburing.patch
+	linux-user-Handle-short-reads-in-mmap_h_gt_g.patch
 
 	$pkgname-guest-agent.confd
 	$pkgname-guest-agent.initd
@@ -594,6 +595,7 @@ d5b4626193fa9b7c687a649aa5ea37d8a74fd2e556a66a71e31af618a0990e144beae253b82b89ef
 7a6340df8aa28811af20cd23b98ba95fc8072d4d4d3a2d497604386396892cf26716d0755821e47d02c8eded203133d7dde100537c117e2a047179e4f93883cf  musl-initialise-msghdr.patch
 7df4b0979d11fb0b7d2dbb073d7249677b0f51381dfbeb1bec2e44d29dd6e1d752468d7f9fb5b42deed6bdf184e81358e7b6dc54b36db326f3336cd6121a1a60  fix-strerrorname_np.patch
 75979455abcd9d9f25a966d829d578a06691163e297247c045ce67f94ebc916850b7be1080024a9db6bba9e3f7b88a8cc486f364fb7b028804862bc8634f00e4  liburing.patch
+7e7e3768215c57dec0ca21f7c4d55174600d4077353b5f596187f8df0b1e4d1baa921ddf696ed69115871c5a4701f0aad81fd6e89b9d19331edd4192d251b168  linux-user-Handle-short-reads-in-mmap_h_gt_g.patch
 d90c034cae3f9097466854ed1a9f32ab4b02089fcdf7320e8f4da13b2b1ff65067233f48809911485e4431d7ec1a22448b934121bc9522a2dc489009e87e2b1f  qemu-guest-agent.confd
 1cd24c2444c5935a763c501af2b0da31635aad9cf62e55416d6477fcec153cddbe7de205d99616def11b085e0dd366ba22463d2270f831d884edbc307c7864a6  qemu-guest-agent.initd
 9b7a89b20fcf737832cb7b4d5dc7d8301dd88169cbe5339eda69fbb51c2e537d8cb9ec7cf37600899e734209e63410d50d0821bce97e401421db39c294d97be2  80-kvm.rules

community/qemu/linux-user-Handle-short-reads-in-mmap_h_gt_g.patch

@@ -0,0 +1,100 @@
+Patch from:
+https://gitlab.com/qemu-project/qemu/-/commit/a4ad4a9d98f7fbde806f07da21e69f39e134cdf1
+
+From a4ad4a9d98f7fbde806f07da21e69f39e134cdf1 Mon Sep 17 00:00:00 2001
+From: Richard Henderson <richard.henderson@linaro.org>
+Date: Fri, 16 Aug 2024 07:13:31 +1000
+Subject: [PATCH] linux-user: Handle short reads in mmap_h_gt_g
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+In particular, if an image has a large bss, we can hit
+EOF before reading all host_len bytes of the mapping.
+
+Create a helper, mmap_pread to handle the job for both
+the larger block in mmap_h_gt_g itself, as well as the
+smaller block in mmap_frag.
+
+Cc: qemu-stable@nongnu.org
+Fixes: eb5027ac618 ("linux-user: Split out mmap_h_gt_g")
+Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2504
+Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
+Message-Id: <20240820050848.165253-2-richard.henderson@linaro.org>
+Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
+---
+ linux-user/mmap.c | 44 ++++++++++++++++++++++++++++++++++++++------
+ 1 file changed, 38 insertions(+), 6 deletions(-)
+
+diff --git a/linux-user/mmap.c b/linux-user/mmap.c
+index 6418e811f6..e4bf5d5f39 100644
+--- a/linux-user/mmap.c
++++ b/linux-user/mmap.c
+@@ -283,6 +283,40 @@ static int do_munmap(void *addr, size_t len)
+     return munmap(addr, len);
+ }
+ 
++/*
++ * Perform a pread on behalf of target_mmap.  We can reach EOF, we can be
++ * interrupted by signals, and in general there's no good error return path.
++ * If @zero, zero the rest of the block at EOF.
++ * Return true on success.
++ */
++static bool mmap_pread(int fd, void *p, size_t len, off_t offset, bool zero)
++{
++    while (1) {
++        ssize_t r = pread(fd, p, len, offset);
++
++        if (likely(r == len)) {
++            /* Complete */
++            return true;
++        }
++        if (r == 0) {
++            /* EOF */
++            if (zero) {
++                memset(p, 0, len);
++            }
++            return true;
++        }
++        if (r > 0) {
++            /* Short read */
++            p += r;
++            len -= r;
++            offset += r;
++        } else if (errno != EINTR) {
++            /* Error */
++            return false;
++        }
++    }
++}
++
+ /*
+  * Map an incomplete host page.
+  *
+@@ -357,10 +391,9 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
+     /* Read or zero the new guest pages. */
+     if (flags & MAP_ANONYMOUS) {
+         memset(g2h_untagged(start), 0, last - start + 1);
+-    } else {
+-        if (pread(fd, g2h_untagged(start), last - start + 1, offset) == -1) {
+-            return false;
+-        }
++    } else if (!mmap_pread(fd, g2h_untagged(start), last - start + 1,
++                           offset, true)) {
++        return false;
+     }
+ 
+     /* Put final protection */
+@@ -853,8 +886,7 @@ static abi_long mmap_h_gt_g(abi_ulong start, abi_ulong len,
+     }
+ 
+     if (misaligned_offset) {
+-        /* TODO: The read could be short. */
+-        if (pread(fd, p, host_len, offset + real_start - start) != host_len) {
++        if (!mmap_pread(fd, p, host_len, offset + real_start - start, false)) {
+             do_munmap(p, host_len);
+             return -1;
+         }
+-- 
+2.46.0
+