| Message ID | 20140319170353.4428b501@redhat.com |
|---|---|
| State | New |
| Headers | show |
Am 19.03.2014 22:03, schrieb Luiz Capitulino: > Linux guests, when using more than 4GB of RAM, may end up using 1GB pages > to store (kernel) data. When this happens, we're unable to debug a running > Linux kernel with GDB: > > (gdb) p node_data[0]->node_id > Cannot access memory at address 0xffff88013fffd3a0 > (gdb) > > GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support > translating 1GB pages in IA-32e paging mode and returns an error to GDB. > > This commit adds support for 1GB page translation for IA32e paging. > > Signed-off-by: Luiz capitulino <lcapitulino@redhat.com> Capitulino? :) > --- > > - I'm proposing this patch for 2.0 because GDB debugging of large Linux > guests is kind of broken Agree that it would be nice to fix, but having mainly touched the function interface, I am dependent on reviewers here. => rc2 or .1 Regards, Andreas > > - Changelog v2: > - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block > - Update changelog > > target-i386/helper.c | 9 +++++++++ > 1 file changed, 9 insertions(+)
On Wed, 19 Mar 2014 22:58:11 +0100 Andreas Färber <afaerber@suse.de> wrote: > Am 19.03.2014 22:03, schrieb Luiz Capitulino: > > Linux guests, when using more than 4GB of RAM, may end up using 1GB pages > > to store (kernel) data. When this happens, we're unable to debug a running > > Linux kernel with GDB: > > > > (gdb) p node_data[0]->node_id > > Cannot access memory at address 0xffff88013fffd3a0 > > (gdb) > > > > GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support > > translating 1GB pages in IA-32e paging mode and returns an error to GDB. > > > > This commit adds support for 1GB page translation for IA32e paging. > > > > Signed-off-by: Luiz capitulino <lcapitulino@redhat.com> > > Capitulino? :) Can you or Peter fix it when merging? > > --- > > > > - I'm proposing this patch for 2.0 because GDB debugging of large Linux > > guests is kind of broken > > Agree that it would be nice to fix, but having mainly touched the > function interface, I am dependent on reviewers here. => rc2 or .1 I think Paolo and/or Jan will review it. > > Regards, > Andreas > > > > > - Changelog v2: > > - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block > > - Update changelog > > > > target-i386/helper.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) >
Il 19/03/2014 22:03, Luiz Capitulino ha scritto: > Linux guests, when using more than 4GB of RAM, may end up using 1GB pages > to store (kernel) data. When this happens, we're unable to debug a running > Linux kernel with GDB: > > (gdb) p node_data[0]->node_id > Cannot access memory at address 0xffff88013fffd3a0 > (gdb) > > GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support > translating 1GB pages in IA-32e paging mode and returns an error to GDB. > > This commit adds support for 1GB page translation for IA32e paging. > > Signed-off-by: Luiz capitulino <lcapitulino@redhat.com> > --- > > - I'm proposing this patch for 2.0 because GDB debugging of large Linux > guests is kind of broken > > - Changelog v2: > - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block > - Update changelog > > target-i386/helper.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/target-i386/helper.c b/target-i386/helper.c > index 4f447b8..7cee501 100644 > --- a/target-i386/helper.c > +++ b/target-i386/helper.c > @@ -941,6 +941,14 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) > pdpe = ldq_phys(cs->as, pdpe_addr); > if (!(pdpe & PG_PRESENT_MASK)) > return -1; > + > + if (pdpe & PG_PSE_MASK) { > + page_size = 1024 * 1024 * 1024; > + pte = pdpe & ~( (page_size - 1) & ~0xfff); > + pte &= ~(PG_NX_MASK | PG_HI_USER_MASK); > + goto out; > + } > + > } else > #endif > { > @@ -993,6 +1001,7 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) > pte = pte & env->a20_mask; > } > > +out: > page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); > paddr = (pte & TARGET_PAGE_MASK) + page_offset; > return paddr; > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Paolo
On 2014-03-19 22:03, Luiz Capitulino wrote: > Linux guests, when using more than 4GB of RAM, may end up using 1GB pages > to store (kernel) data. When this happens, we're unable to debug a running > Linux kernel with GDB: > > (gdb) p node_data[0]->node_id > Cannot access memory at address 0xffff88013fffd3a0 > (gdb) > > GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support > translating 1GB pages in IA-32e paging mode and returns an error to GDB. > > This commit adds support for 1GB page translation for IA32e paging. > > Signed-off-by: Luiz capitulino <lcapitulino@redhat.com> > --- > > - I'm proposing this patch for 2.0 because GDB debugging of large Linux > guests is kind of broken > > - Changelog v2: > - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block > - Update changelog > > target-i386/helper.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/target-i386/helper.c b/target-i386/helper.c > index 4f447b8..7cee501 100644 > --- a/target-i386/helper.c > +++ b/target-i386/helper.c > @@ -941,6 +941,14 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) > pdpe = ldq_phys(cs->as, pdpe_addr); > if (!(pdpe & PG_PRESENT_MASK)) > return -1; > + > + if (pdpe & PG_PSE_MASK) { > + page_size = 1024 * 1024 * 1024; > + pte = pdpe & ~( (page_size - 1) & ~0xfff); > + pte &= ~(PG_NX_MASK | PG_HI_USER_MASK); > + goto out; > + } > + > } else > #endif > { > @@ -993,6 +1001,7 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) > pte = pte & env->a20_mask; > } > > +out: > page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); > paddr = (pte & TARGET_PAGE_MASK) + page_offset; > return paddr; > Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
On Wed, 19 Mar 2014 17:03:53 -0400 Luiz Capitulino <lcapitulino@redhat.com> wrote: > Linux guests, when using more than 4GB of RAM, may end up using 1GB pages > to store (kernel) data. When this happens, we're unable to debug a running > Linux kernel with GDB: > > (gdb) p node_data[0]->node_id > Cannot access memory at address 0xffff88013fffd3a0 > (gdb) > > GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support > translating 1GB pages in IA-32e paging mode and returns an error to GDB. > > This commit adds support for 1GB page translation for IA32e paging. Peter, can you pick up this one please? > > Signed-off-by: Luiz capitulino <lcapitulino@redhat.com> > --- > > - I'm proposing this patch for 2.0 because GDB debugging of large Linux > guests is kind of broken > > - Changelog v2: > - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block > - Update changelog > > target-i386/helper.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/target-i386/helper.c b/target-i386/helper.c > index 4f447b8..7cee501 100644 > --- a/target-i386/helper.c > +++ b/target-i386/helper.c > @@ -941,6 +941,14 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) > pdpe = ldq_phys(cs->as, pdpe_addr); > if (!(pdpe & PG_PRESENT_MASK)) > return -1; > + > + if (pdpe & PG_PSE_MASK) { > + page_size = 1024 * 1024 * 1024; > + pte = pdpe & ~( (page_size - 1) & ~0xfff); > + pte &= ~(PG_NX_MASK | PG_HI_USER_MASK); > + goto out; > + } > + > } else > #endif > { > @@ -993,6 +1001,7 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) > pte = pte & env->a20_mask; > } > > +out: > page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); > paddr = (pte & TARGET_PAGE_MASK) + page_offset; > return paddr;
diff --git a/target-i386/helper.c b/target-i386/helper.c index 4f447b8..7cee501 100644 --- a/target-i386/helper.c +++ b/target-i386/helper.c @@ -941,6 +941,14 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) pdpe = ldq_phys(cs->as, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) return -1; + + if (pdpe & PG_PSE_MASK) { + page_size = 1024 * 1024 * 1024; + pte = pdpe & ~( (page_size - 1) & ~0xfff); + pte &= ~(PG_NX_MASK | PG_HI_USER_MASK); + goto out; + } + } else #endif { @@ -993,6 +1001,7 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) pte = pte & env->a20_mask; } +out: page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); paddr = (pte & TARGET_PAGE_MASK) + page_offset; return paddr;
Linux guests, when using more than 4GB of RAM, may end up using 1GB pages to store (kernel) data. When this happens, we're unable to debug a running Linux kernel with GDB: (gdb) p node_data[0]->node_id Cannot access memory at address 0xffff88013fffd3a0 (gdb) GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support translating 1GB pages in IA-32e paging mode and returns an error to GDB. This commit adds support for 1GB page translation for IA32e paging. Signed-off-by: Luiz capitulino <lcapitulino@redhat.com> --- - I'm proposing this patch for 2.0 because GDB debugging of large Linux guests is kind of broken - Changelog v2: - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block - Update changelog target-i386/helper.c | 9 +++++++++ 1 file changed, 9 insertions(+)