From bde971a83bbff78561458ded236605a365411b87 Mon Sep 17 00:00:00 2001 From: Denis Nikitin Date: Fri, 14 Oct 2022 11:45:32 -0700 Subject: KVM: arm64: nvhe: Fix build with profile optimization Kernel build with clang and KCFLAGS=-fprofile-sample-use= fails with: error: arch/arm64/kvm/hyp/nvhe/kvm_nvhe.tmp.o: Unexpected SHT_REL section ".rel.llvm.call-graph-profile" Starting from 13.0.0 llvm can generate SHT_REL section, see https://reviews.llvm.org/rGca3bdb57fa1ac98b711a735de048c12b5fdd8086. gen-hyprel does not support SHT_REL relocation section. Filter out profile use flags to fix the build with profile optimization. Signed-off-by: Denis Nikitin Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221014184532.3153551-1-denik@chromium.org --- arch/arm64/kvm/hyp/nvhe/Makefile | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index 48f6ae7cc6e6..be0a2bc3e20d 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -92,6 +92,10 @@ quiet_cmd_hypcopy = HYPCOPY $@ # Remove ftrace, Shadow Call Stack, and CFI CFLAGS. # This is equivalent to the 'notrace', '__noscs', and '__nocfi' annotations. KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_CFI), $(KBUILD_CFLAGS)) +# Starting from 13.0.0 llvm emits SHT_REL section '.llvm.call-graph-profile' +# when profile optimization is applied. gen-hyprel does not support SHT_REL and +# causes a build failure. Remove profile optimization flags. +KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%, $(KBUILD_CFLAGS)) # KVM nVHE code is run at a different exception code with a different map, so # compiler instrumentation that inserts callbacks or checks into the code may -- cgit v1.2.3-58-ga151 From c000a2607145d28b06c697f968491372ea56c23a Mon Sep 17 00:00:00 2001 From: Eric Ren Date: Sat, 15 Oct 2022 11:19:28 +0800 Subject: KVM: arm64: vgic: Fix exit condition in scan_its_table() With some PCIe topologies, restoring a guest fails while parsing the ITS device tables. Reproducer hints: 1. Create ARM virt VM with pxb-pcie bus which adds extra host bridges, with qemu command like: ``` -device pxb-pcie,bus_nr=8,id=pci.x,numa_node=0,bus=pcie.0 \ -device pcie-root-port,..,bus=pci.x \ ... -device pxb-pcie,bus_nr=37,id=pci.y,numa_node=1,bus=pcie.0 \ -device pcie-root-port,..,bus=pci.y \ ... ``` 2. Ensure the guest uses 2-level device table 3. Perform VM migration which calls save/restore device tables In that setup, we get a big "offset" between 2 device_ids, which makes unsigned "len" round up a big positive number, causing the scan loop to continue with a bad GPA. For example: 1. L1 table has 2 entries; 2. and we are now scanning at L2 table entry index 2075 (pointed to by L1 first entry) 3. if next device id is 9472, we will get a big offset: 7397; 4. with unsigned 'len', 'len -= offset * esz', len will underflow to a positive number, mistakenly into next iteration with a bad GPA; (It should break out of the current L2 table scanning, and jump into the next L1 table entry) 5. that bad GPA fails the guest read. Fix it by stopping the L2 table scan when the next device id is outside of the current table, allowing the scan to continue from the next L1 table entry. Thanks to Eric Auger for the fix suggestion. Fixes: 920a7a8fa92a ("KVM: arm64: vgic-its: Add infrastructure for tableookup") Suggested-by: Eric Auger Signed-off-by: Eric Ren [maz: commit message tidy-up] Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/d9c3a564af9e2c5bf63f48a7dcbf08cd593c5c0b.1665802985.git.renzhengeek@gmail.com --- arch/arm64/kvm/vgic/vgic-its.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 24d7778d1ce6..733b53055f97 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -2149,7 +2149,7 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, u32 esz, memset(entry, 0, esz); - while (len > 0) { + while (true) { int next_offset; size_t byte_offset; @@ -2162,6 +2162,9 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, u32 esz, return next_offset; byte_offset = next_offset * esz; + if (byte_offset >= len) + break; + id += next_offset; gpa += byte_offset; len -= byte_offset; -- cgit v1.2.3-58-ga151