From: Gerd Hoffmann <kraxel@redhat.com> To: Anthony PERARD <anthony.perard@citrix.com> Cc: qemu-devel@nongnu.org, xen-devel@lists.xen.org, Stefano Stabellini <sstabellini@kernel.org>, Paolo Bonzini <pbonzini@redhat.com> Subject: Re: [Qemu-devel] Change of max-ram-below-4g initial value breaks Xen Date: Thu, 23 Jun 2016 16:57:54 +0200 [thread overview] Message-ID: <1466693874.26189.50.camel@redhat.com> (raw) In-Reply-To: <20160622150937.GS5666@perard.uk.xensource.com> [-- Attachment #1: Type: text/plain, Size: 343 bytes --] Hi, > How could xen_ram_init() find out if the value of max-ram-below-4g is > the default or if a user have set it? Is there another way we could fix > this? Attached patch should fix it. Patch survived a quick smoke test on kvm so far, need to do some more testing tomorrow. Can you give it a spin on xen? thanks, Gerd [-- Attachment #2: 0001-xen-fix-ram-init-regression.patch --] [-- Type: text/x-patch, Size: 3039 bytes --] From d45a95861def18a02e1c26d3717693432517107a Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann <kraxel@redhat.com> Date: Thu, 23 Jun 2016 16:49:03 +0200 Subject: [PATCH] xen: fix ram init regression Commit "8156d48 pc: allow raising low memory via max-ram-below-4g option" causes a regression on xen, because it uses a different memory split. This patch initializes max-ram-below-4g to zero and leaves the initialization to the memory initialization functions. That way they can pick different default values (max-ram-below-4g is zero still) or use the user supplied value (max-ram-below-4g is non-zero). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- hw/i386/pc.c | 2 +- hw/i386/pc_piix.c | 3 +++ hw/i386/pc_q35.c | 3 +++ xen-hvm.c | 3 +++ 4 files changed, 10 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 7198ed5..66e1dae 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1886,7 +1886,7 @@ static void pc_machine_initfn(Object *obj) pc_machine_get_hotplug_memory_region_size, NULL, NULL, NULL, &error_abort); - pcms->max_ram_below_4g = 0xe0000000; /* 3.5G */ + pcms->max_ram_below_4g = 0; /* use default */ object_property_add(obj, PC_MACHINE_MAX_RAM_BELOW_4G, "size", pc_machine_get_max_ram_below_4g, pc_machine_set_max_ram_below_4g, diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 53bc968..78e3d44 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -114,6 +114,9 @@ static void pc_init1(MachineState *machine, * qemu -M pc,max-ram-below-4g=2G -m 4G -> 2048M low, 2048M high * qemu -M pc,max-ram-below-4g=4G -m 3968M -> 3968M low (=4G-128M) */ + if (!pcms->max_ram_below_4g) { + pcms->max_ram_below_4g = 0xe0000000; /* default: 3.5G */ + } lowmem = pcms->max_ram_below_4g; if (machine->ram_size >= pcms->max_ram_below_4g) { if (pcmc->gigabyte_align) { diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index e4b541f..1b653e2 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -93,6 +93,9 @@ static void pc_q35_init(MachineState *machine) /* Handle the machine opt max-ram-below-4g. It is basically doing * min(qemu limit, user limit). */ + if (!pcms->max_ram_below_4g) { + pcms->max_ram_below_4g = 1ULL << 32; /* default: 4G */; + } if (lowmem > pcms->max_ram_below_4g) { lowmem = pcms->max_ram_below_4g; if (machine->ram_size - lowmem > lowmem && diff --git a/xen-hvm.c b/xen-hvm.c index 98ea44f..eb57792 100644 --- a/xen-hvm.c +++ b/xen-hvm.c @@ -190,6 +190,9 @@ static void xen_ram_init(PCMachineState *pcms, /* Handle the machine opt max-ram-below-4g. It is basically doing * min(xen limit, user limit). */ + if (!user_lowmem) { + user_lowmem = HVM_BELOW_4G_RAM_END; /* default */ + } if (HVM_BELOW_4G_RAM_END <= user_lowmem) { user_lowmem = HVM_BELOW_4G_RAM_END; } -- 1.8.3.1
WARNING: multiple messages have this Message-ID (diff)
From: Gerd Hoffmann <kraxel@redhat.com> To: Anthony PERARD <anthony.perard@citrix.com> Cc: Paolo Bonzini <pbonzini@redhat.com>, Stefano Stabellini <sstabellini@kernel.org>, qemu-devel@nongnu.org, xen-devel@lists.xen.org Subject: Re: Change of max-ram-below-4g initial value breaks Xen Date: Thu, 23 Jun 2016 16:57:54 +0200 [thread overview] Message-ID: <1466693874.26189.50.camel@redhat.com> (raw) In-Reply-To: <20160622150937.GS5666@perard.uk.xensource.com> [-- Attachment #1: Type: text/plain, Size: 343 bytes --] Hi, > How could xen_ram_init() find out if the value of max-ram-below-4g is > the default or if a user have set it? Is there another way we could fix > this? Attached patch should fix it. Patch survived a quick smoke test on kvm so far, need to do some more testing tomorrow. Can you give it a spin on xen? thanks, Gerd [-- Attachment #2: 0001-xen-fix-ram-init-regression.patch --] [-- Type: text/x-patch, Size: 3039 bytes --] From d45a95861def18a02e1c26d3717693432517107a Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann <kraxel@redhat.com> Date: Thu, 23 Jun 2016 16:49:03 +0200 Subject: [PATCH] xen: fix ram init regression Commit "8156d48 pc: allow raising low memory via max-ram-below-4g option" causes a regression on xen, because it uses a different memory split. This patch initializes max-ram-below-4g to zero and leaves the initialization to the memory initialization functions. That way they can pick different default values (max-ram-below-4g is zero still) or use the user supplied value (max-ram-below-4g is non-zero). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- hw/i386/pc.c | 2 +- hw/i386/pc_piix.c | 3 +++ hw/i386/pc_q35.c | 3 +++ xen-hvm.c | 3 +++ 4 files changed, 10 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 7198ed5..66e1dae 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1886,7 +1886,7 @@ static void pc_machine_initfn(Object *obj) pc_machine_get_hotplug_memory_region_size, NULL, NULL, NULL, &error_abort); - pcms->max_ram_below_4g = 0xe0000000; /* 3.5G */ + pcms->max_ram_below_4g = 0; /* use default */ object_property_add(obj, PC_MACHINE_MAX_RAM_BELOW_4G, "size", pc_machine_get_max_ram_below_4g, pc_machine_set_max_ram_below_4g, diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 53bc968..78e3d44 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -114,6 +114,9 @@ static void pc_init1(MachineState *machine, * qemu -M pc,max-ram-below-4g=2G -m 4G -> 2048M low, 2048M high * qemu -M pc,max-ram-below-4g=4G -m 3968M -> 3968M low (=4G-128M) */ + if (!pcms->max_ram_below_4g) { + pcms->max_ram_below_4g = 0xe0000000; /* default: 3.5G */ + } lowmem = pcms->max_ram_below_4g; if (machine->ram_size >= pcms->max_ram_below_4g) { if (pcmc->gigabyte_align) { diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index e4b541f..1b653e2 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -93,6 +93,9 @@ static void pc_q35_init(MachineState *machine) /* Handle the machine opt max-ram-below-4g. It is basically doing * min(qemu limit, user limit). */ + if (!pcms->max_ram_below_4g) { + pcms->max_ram_below_4g = 1ULL << 32; /* default: 4G */; + } if (lowmem > pcms->max_ram_below_4g) { lowmem = pcms->max_ram_below_4g; if (machine->ram_size - lowmem > lowmem && diff --git a/xen-hvm.c b/xen-hvm.c index 98ea44f..eb57792 100644 --- a/xen-hvm.c +++ b/xen-hvm.c @@ -190,6 +190,9 @@ static void xen_ram_init(PCMachineState *pcms, /* Handle the machine opt max-ram-below-4g. It is basically doing * min(xen limit, user limit). */ + if (!user_lowmem) { + user_lowmem = HVM_BELOW_4G_RAM_END; /* default */ + } if (HVM_BELOW_4G_RAM_END <= user_lowmem) { user_lowmem = HVM_BELOW_4G_RAM_END; } -- 1.8.3.1 [-- Attachment #3: Type: text/plain, Size: 126 bytes --] _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2016-06-23 14:58 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-22 15:09 [Qemu-devel] Change of max-ram-below-4g initial value breaks Xen Anthony PERARD 2016-06-22 15:09 ` Anthony PERARD 2016-06-22 15:27 ` Gerd Hoffmann 2016-06-22 15:27 ` [Qemu-devel] " Gerd Hoffmann 2016-06-23 14:57 ` Gerd Hoffmann [this message] 2016-06-23 14:57 ` Gerd Hoffmann 2016-06-23 16:18 ` [Qemu-devel] " Anthony PERARD 2016-06-23 16:18 ` Anthony PERARD 2016-06-24 5:46 ` Gerd Hoffmann 2016-06-24 5:46 ` [Qemu-devel] " Gerd Hoffmann 2016-06-24 11:19 ` Anthony PERARD 2016-06-24 11:19 ` [Qemu-devel] " Anthony PERARD
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